One of the most universally popular and timeless forms of serious amateur and professional photography is the noble landscape image. I do not confess to being an obsessed landscaper, but have dabbled and assisted other, more focussed photographers (living in Tasmania kind of makes you a landscape photographer by default), so I hope I can impart some limited wisdom on the subject.
Personal visions vary immensely, but landscape work is consistent in what it requires and what it delivers.
This is the one area of digital photography that can genuinely benefit from more pixels, but only if used carefully. Enlargements tend to be on the bigger side, and lots of small details are the norm. Technique is the key here though. A good tripod and an understanding of the many ways to arrest micro movements during exposure will be of benefit. Terms like "mirror lock", anti shock, self timers or cable releases, tripod collars around long lenses (for better balance) and "weighted" tripods are commonly used terms amongst the initiated.
An important thing to do is look at images taken for landscape competitions such as the "AA" British Landscape Photographer of the Year awards. These are a bit of an eye opener, first for their amazing content and then for the gear used (especially in the kids and compact camera sections). One class winner created a photo using a full frame camera and multiple stitched images. A runner up in the same section, created a similar image from the same place, with the same lens, but with a single capture from a crop frame 10mp camera! Up to A3 size, the difference would be minimal, but bigger sizes would show more detail in the larger file.
The camera does not have to be a monstrous speed machine, on the contrary, size and weight are important also as the destination may be well off the beaten track (weatherproofing is handy though). Full frame cameras are not as important as in other styles as the photographer will usually have plenty of time (to find and take the image), so high pixel counts do not have to be balanced against poorer low light performance (the benefit of a full frame is better high ISO performance). By contrast, smaller sensor cameras have depth of field benefits and can often match their full frame counterparts in file size (24mp is the current overlap). A gentle shutter action can be the difference between a poor scenic camera and a good one. Some consideration should also be given to the new "super" compacts sporting sharp lenses, 20 MP 1" sensors, electronic shutters and tiny body form as they exceed the performance of even recent DSLR cameras.
In a nutshell; small, light, smooth shooting, reliable and mid to high pixels...easy.
More good news is that lenses can be selected from a wider range as the landscaper will often "stop down" their lens aperture for good depth of field and sharpest settings, giving all lenses a fighting chance and reducing the differences between "Pro" and middle of the road lenses. Even kit lenses used well will be able to resolve the bulk of detail available on the camera's sensor. Have a look at lens testing sites such as slrgear.com and compare the best premium offerings to the middle of the range zooms at f8-16. There is often a huge difference at extreme apertures and focal lengths, but in the middle apertures the numbers are usually pretty close. In the field much of this does not matter.
So, well researched "middle" grade lenses, not super fast and heavy are ideal. Good examples are the Canon 70-200 f4L (non IS) and 17-40 f4L. Super sharp at most landscape users settings, sub 1kg/$900 au, loosing one maximum F stop to the top lenses (up to twice as heavy and three times as expensive) and no stabiliser (which is useless on a tripod anyway).
Another factor to consider when kitting up with your landscape lenses is your focal length choice. Many assume that a wide angle lens is the staple for most landscapers, but that is often not the case. Some use longer lenses more often than not, looking for details, compression and "order out of chaos" in their images, others use standard or natural perspective lenses and stitch together panoramic photos rather than the usual, distorted perspective, wide angle lens normally used.
As some small proof of the above statements, the above photo was taken with a $599 camera and lens combo (Fuji XA-1 and 16-50 kit lens). It can enlarged to gallery sizes, is sharp edge to edge and shows no other signs of being stretched too far. It is also a 16mp jpeg.
As stated above, the important thing in landscape photography (all types, but especially landscape) is solid, organised technique. In the days of 35mm film, the photographer was effectively stagnant in possible quality growth as new film and developers, lenses and cameras can along rarely (Fuji Velvia when it was released literally changed landscape photography and dominated it for 20 years; Kodachrome owned the previous era). When they did come, they changed little in real terms. Quality came down to good equipment used with good technique. The expert was organised, pragmatic and focussed (no pun intended). It was often confusing to the newcomer why their photos did not come up to the standard of their idols when they used the same gear (not too hard to achieve then either as choice was more limited). These days we assume the "better camera" was the reason, but the successful photographer knows better. Technique is still king. If this was not the case, we would be seeing a constant increase in visible quality and older photos would not be able to compete. This is not the case. The colour work of Ansel Adams from the 1930's is sublime, bullet proof to technical criticism and he did not even like to shoot colour! Admittedly he used a large format camera, but so could anyone else with equal effort.
This is the big one and where I personally fall down.
All landscape photographers learn the true importance of time. This comes in a lot of forms from getting up before, or staying out after the sun, trekking to the distant locale and being patient when there or just revisiting the same locale until the magic happens. Often the difference between a good landscape photo and a great one is a couple of minutes, but it can be a couple of hours. Getting back to technique, it's really important to be organised and prepared so you can be ready to get that fleeting moment. There is no point being in the right place at the right time and having to set up your tripod, put the tripod foot on your camera, reverse your hood, take off the cap, change a neglected battery, put on/take off a filter (removing the hood again), find and attach a cable release, change mode and look up.....the light is gone.
Be ready for your next shot after your last. This includes on your way back home. Film shooters often left one "in the can" just in case. Organise your camera bag to be able to place any configuration of lens and camera you may want so as to reduce unwanted fiddle just to fit things in.
I hope this helps.