When I first tried to port my tmux config to wezterm it took about a day to learn about all the wezterm concepts, map them to their tmux equivalents, and reach an mvp. I tend to be on the slower side to pick things up though.
Locally - I far prefer wezterm now. The only issue for me was that getting persistent server side sessions seemed to come at the cost of some weird neovim gui refresh and latency issues which I'm not sure are fully solved yet, so I still use tmux for that. Looking at the issue tracker, maybe I should try again, seems that at least some refresh issues have been addressed since I last checked https://github.com/wezterm/wezterm/issues/4607