@Drmowinckels both vim and neovim have a built in terminal now, which I agree is an absolute non negotiable item to use R to its fullest with a REPL.
This is not a recommendation exactly but if you’re looking to round out your R editor experience you could give emacs + ESS a go. In particular the way they do help is excellent, and inspired me to try to recreate it in RStudio/VSCode with {rmdocs}.