Need a quality camera for hiking

I would either suggest a mirrorless camera or a small dslr with AF micro adjust (canon).

The beauty of mirrorless is that you'll seldom have back/front focus (sony/fuji) If you go micro 4/3 the newer bodies will have very good focus too (panasonic proprietary DFD or olympus hybrid phase detect/contrast detect AF).

I cannot ever buy a dslr with no micro adjust due to the chances of having a lens miss focus due to the tolerance of calibration of the camera body vs lens calibration.

I recently purchases a cheap Canon 50mm f/1.8 STM prime just as a throw around for my 80D. The shaprness at f/1.8 was very good with some AF micro adjusting and reasonably sharp as I moved away from the subject. Testing that same lens with my 5d3 and 5d2 that lens was not as sharp even when micro adjusting and the approximately 7 feet away the test subject was soft and a blur. I returned it happily!!!

With my fuji I've never ever experienced soft images. Extremely spoiled that every lens works perfectly with no focus issues !!!!

OP not sure in your area but if your going through the troubles of saving weight mirrorless is the way to go. If you just want a smaller dlsr I am extremely pleased with the IQ I am getting with my 80D. Slightly larger than a rebel series but the performance is incredible.

If your not using flash I'll have to say my fuji with 18-55 kit lens ($1000 range) would surpass the IQ of a high percentage of older gen canon crop sensors with $$$ lenses. I still feel the IQ from my 80D with 16-35 f/2.8mk2 is not as good as my fuji with kit lens!!!

Have you considered a one size fits all camera? I've heard really good things about the Sony RX-10 series. A RX-10 II can be had for relatively cheap I would guess. And the RX10-III while a bit more expensive would provide much more reach. They both have amazing video features as well if you're into that. Would save on weight too.

I've got over 4000 miles logged backpacking, and at my age the feet/knees/lower back to prove it.
OP mentioned wanting interchangeable lenses and for me that has historically been a Pandora's box of
just one more lens, and another, and another.
Youth and strength must be added into your equation and what ultimate image quality you desire compared
to the amount of weight you want to suffer.

For years I backpacked with a Nikon F2 Photomic In a not too distant past I'd settled on mFT and three lenses.

We have a hike coming up in February, full winter on with temps expected to be 5F and below....obviously my priorities
will be warmth and not picture IQ.
For that hike it will be an RX100v, a Sony HX80, and a super dinky travel tripod for the group photo.

For years I tried searching for the perfect lightweight camera set up for travel/biking. I was never happy with m4/3 after trying Olympus and Panasonic cameras.

I ended up going with a Canon T3i outfit. The Nikon D3000/5000 series dslr's are even lighter. The IQ from any crop sensor, entry level dslr camera is vastly superior (imo) than any m4/3 or smaller sensor camera out there. Also, entry level dslr outfits are sometimes less expensive than offerings from m4/3 outfits.

One more view from another person who had the same issues with balancing weight/performance.

I am pretty invested in the Canon system and had a 5D3 which was far too heavy. I bought a 100D (SL1) and 3 STM lenses (24mm, 40mm and 50mm). This is a neat lightweight system but I was never satisfied with it. The 100D is terrible for ISO > 400, changing lenses was a nightmare in the wind and rain on the Scottish hills and I was constantly having to take multiple images and stitch them in post as the 24mm on crop just wasn't wide enough. So I sold all the STM lenses and bought a 6D and 24-70mm L f/4 and have never looked back. In fact the combo rolled down a hill and only stopped when it hit a rock. The 6D survived but the lens did not, so I bought another one. The combo is that good IMHO. In addition the lens has a Macro function (not true macro) which is so useful if you are out in the wild. I carry a small tripod and the small IR remote control and that's all I need. Of course the lens is used on my other cameras as well and the 6D is used as a second camera for weddings. I wouldn't be without it.