I think the lowest hanging fruit would be doing something (anything) to improve discovery of commands. I have great grokking abilities but terrible memorization skills, and I end up forgetting how to do what I want to do and maybe even have done before. Browsing man pages for every command is my bane. It's also why I dislike GUI with unlabelled icons, I never remember what each one does.
Maybe try fish? Tab completion will suggest subcommands, and if you type - or -- and hit tab, it will suggest the available options with help text generated from man pages (example: https://flaviocopes.com/images/fish-shell/autocomplete.png). Doesn't really help with positional arguments but it's definitely enhanced the discoverability of many tools for me.
At this point Google has basically taken over that function... "How do I _ on the command line?" more often than not gives one some starting point to develop from.
GPT is great at this. I wrote a little program that I can call from a shell. Bashai.py show me a bash one liner that does x. It then shows me the command and asks if I want to run it with or without root. Simple, yet one of the best tools I've ever made for myself.
