Yeah they seem that way as well, never had noticed. 21.6mm for Q1 is a lot (and that's not the effective keyboard height as well, so in practice it feels even higher than that)
Generally you want to do hover typing, putting your wrists on the ground is actually improper, and generally the height you have to hover hand is not really a factor to ergonomics. You will probably get used to it within time. People get used to other boards with large front heights like duck boards (though I think this might be higher than even them)
So basically the only ergonomic problem with the keychrons is if you don't type with hover hand, then it could cause more strain on the hands (as well as being not that great to type on for those people in general)