As an example Alacritty+tmux feels wayyy slower than iTerm for tabs/splitting.

Tmux also comes with some limitations that make it annoying (to me) to use 100% of the time :

- scroll back is painful compared to native terminal emulator scrollback, so is mouse support

- rendering gets slowed down by tmux because it parses the output itself, the fastest terminal emulator with tmux will feel slower than iTerm without tmux

- some TUIs work badly in tmux, neovim for instance. I’ve also had issues with htop in the past

Tmux is a great tool, but I can’t conceive using it by default, it’s too janky for that.