i've got ~20 bashes open in various tmux configurations. the amount of times i lost command history is infuriating (e.g. due to reboot or whatever).

context-sensitive completion (not necesarrily tab completion, mind you) is very basic compared to IDEs.

mouse support would be good if it was actually useful. copy and paste is useful.

zoom in/out (think c--/c-+/c-0 in browsers) would be nice sometimes, especially when i want to copy large amounts of stuff. the fact that copy/paste is the easiest way to transfer files over ssh is also mildly irritating.

option to display an image or render a webpage or pdf in the terminal directly (ala jupyter) would be nice.