Bhopping was easier on 64 tick, you had a longer timeframe to trigger the jump. You have to hit the tick where you land with you scrollwheel, which you have double the chance to in 64 tick.
In new subtick, bhop ability is dependant on the jump_penalty value that is sv_cheats protected and was changed by Valve already weeks ago. Go private server and play around with the values yourself.
Subtick works, but the animations and viewmodel are based on triggered when you client receives the package from the server which happens end the end of the tick + ping delay, that's why it feels off. They could do it clientsided and but that would probably mess something else up with interpolation or open opportunity to abuse and cheats.
Best bet is they somehow use AI to refine their interpolation, or use 128 tick which would reduce the delay by ~7ms but wouldn't solve the problem. Most people have 20-30ms ping delay anyways and that has nothing to do with tickrate.