You say the small things. You mean like, how quickly the terminal opens and how quickly text gets painted on the screen?
iTerm2 blows hyper out of the water in those regards, and it actually does add up. Styling otherwise really isn't that difficult, but it begs the question of why do you need so much information? Are you actually developing or just spending time tinkering on your terminal to have bells and whistles that you don't actually even look at? Surely a simple colorscheme + font that aliases correctly should be enough to "feel nice" to look at?
The only thing keeping me from the better performance of alacritty is iterm2's infinite scrollback and some other miscellaneous features that alacritty will probably never get.