Ive spent a lot of time hiking through parks like Zion and honestly, weight is the one thing people always underestimate until they are halfway up a trail. For a trip like this, Id personally steer clear of the Sigma 14-24mm f/2.8 DG DN Art. Over the years Ive learned that carrying a pound and a half of glass is just exhausting, and since you will be shooting at f/8 or f/11 most of the time anyway, that f/2.8 aperture is basically just extra weight you dont need for landscapes. Plus, that lens has a bulbous front element which makes using standard filters a total nightmare and risky in dusty canyons. In my experience, the Sony FE 16-35mm f/4 PZ G is actually the smarter move for your a7IV. People get hung up on the power zoom being for video, but the optics are genuinely impressive for stills and its incredibly light. Another solid option if you want to save some cash and still get great results is the Tamron 17-28mm f/2.8 Di III RXD. Its been very reliable for me on long treks and takes simple 67mm filters which is way safer for your front element. Stick with the Sony though if you can. Its weather sealed and the internal zoom means less chance of sand getting inside the barrel while you are out in the desert wind. You will be much happier on those long hikes with a lighter setup and the files will look plenty sharp for those large prints.

Finally someone says it. Ive been thinking this for a while but wasnt sure.