Type on what feels good to you. My favorite keyboards are mechanical (the Matias Mini Tactile Pro, nearly tied with a Vortex 3 using Cherry MX Clears), but my next favorite is Apple's Magic Keyboard. So much of this is ultimately subjective. The Tactile Pro key switches are absurdly loud, but the MX Clears really aren't, and I've been able to type 100+ words per minute on nearly all good keyboards -- the only ones that really throw me off are Apple's unlamented "butterfly" keyboard design and membrane-switch chiclets.
But, all I can say is "worse typing" is, well, super subjective. I type at least as well on mechanical keyboards, and I find my fingers don't get as tired when I'm using them. For what it's worth, I'm in my 50s, have been using mechanical keyboards for as much of the nearly 40 years I've been dorking with computers, and I've had very few RSI-related problems. I think I've been pretty good about ergonomics across the board, so I'm not going to ascribe that solely to keyswitches -- but I think they've definitely helped.
But, all I can say is "worse typing" is, well, super subjective. I type at least as well on mechanical keyboards, and I find my fingers don't get as tired when I'm using them. For what it's worth, I'm in my 50s, have been using mechanical keyboards for as much of the nearly 40 years I've been dorking with computers, and I've had very few RSI-related problems. I think I've been pretty good about ergonomics across the board, so I'm not going to ascribe that solely to keyswitches -- but I think they've definitely helped.