I was completely brainwashed by the community that mechanical keyboards were the solution to RSI and had a major blind spot. I even learned dvorak and got up to near 100wpm at it with no success.
When I ditched the mechanical keyboards all the problems went away.
Something about the whole thing with the tactile bump in the middle doesn't work for me. When my typing ramps up to high speed I end up pushing the mechanical key all the way down to the stop anyway and blowing through the tactile bump. Once you're doing that you're moving your fingers further and doing more work, and the stops on these key switches are harder than a lot of non-mechanical keyboards.
No doubt they feel great and I do think I can type faster on them but unquestionably for me the Cherry MX type switches give me RSI symptoms and tendonitis in my arms.
I think it's all in the travel & how the "stop" at the end of the travel feels. I have a bunch of experience playing guitar and piano too.. piano has a long travel, if the stop at the end of the travel is hard it gives me RSI, but if it's not (and it's usually not on real acoustic piano keybeds) it's mostly OK. Guitar meanwhile has a rock hard stop but minimal travel, and a good guitar you also get some tactile feedback in that if you push the note down too far it goes sharp. Guitar basically gives me 0 RSI symptoms. A lot of these Cherry type mechanical keyswitches are the worst of both worlds.. long travel and a very hard/harsh stop at the bottom of the travel.
Both the modern MS and Apple keyboards are mostly fine and I've been feeling great for about 6 years now since ditching the mechanical key switches.
I think buckling spring might not cause me issues FWIW, but I tried a lot of mechanical KBs including TEK, Kinesis, different Das Keyboard models.. anything with a Cherry style switch (Actual Cherry MX or clones) gives me trouble.