The worst part is they call it an intentional choice. "First off, premoves take 0.1 seconds. That is what has been preferred and agreed upon by most professional players we have consulted on the topic. They prefer .1 to .0 for premove. This is also what other chess servers do."[1]

It's super annoying and the reason I only play blitz+ on chesscom.

[1]https://www.chess.com/forum/view/help-support/mate-in-one-qu...