1. I use it as a wifi access point with hostapd. Where i live net is shared with many residents. This way my devices are isolated from others.
2. I portforward ssh from main wifi router to rpi, when im not at home i can ssh into it and use it at as poor's man vpn - handy at airports/pubs..
3. Its attached to tv via hdmi, i can watch youtube/twitch with it fairly ok (better then most "smart tvs" anyway with ff and ublock).
4. It serves as a "backup", i have usb 1tb hd and some scripts that mirror my github/gitlab repos, this is more as a precaution then as its "real" backup, but if i ever need it i could make it better with md raid i guess.
So, with all above, its a nice device to have for me at least, its not wasted 50-60e :)
Notes are just that, notes, they are extension of my thoughts and thinking process, no company can own those, so no, i have not discuss that with any company i have worked with, but to give more context, im not storing anything sensational there (code snippets, ideas, bash oneliners, config snippets, screenshots sometimes, links to various things etc... )
Its just a helper tool for me to get job done, and that is what matters most i think.
Another thing, after some time amount of "knowlegde" piles up really nicely, so the other day i needed some selinux magic for example. Few years ago i have worked with it, but over time i have forgot number of smaller details. So i reach org file called selinux.org where i have captured lots of details - notes if you like, on how whole damn thing works.. in a few hours i was already "productive" and with few extra ideas.. you get the idea..
One thing to note with this approach is that you wont see git diff, as encrypted files are blobs, so you have to be careful with it (its easy to overwrite something)... also, in two-three years, git repo size (depending on your usage) becomes/can become pretty large..
Other then that, its really good setup, and say you dont really fancy emacs/org-mode, you can pull same thing with encrypted text files/folders!