We both know that approximately 24 hours after donating something he will BADLY need it for an unexpected repair.

Then he can borrow it from the library he donated it to :)

I'm always worried that some less skilled user will have broken or not maintained it. I don't know how maker spaces get around this

Usually they have volunteers who do maintenance. At my local tool library the tools are well-used, but there's also like 10 of everything so you have lots of backup options.

most places i’ve borrowed things will seek some basic assurances that i know what i’m doing, first.

for example, when i borrowed a MIG welder, the person at the space asked me to weld some scrap metal in front of them before they let me loose with it.

This is easier than many assume: If you can find the Discord or even an e-mail for your local makerspace and send them a photo, they might urgently send someone to pick it up from you if it's useful to them.

Is a local tool library or hackerspace something common? I’ve never heard of that but that sounds cool

tool libraries exist in most cities and a lot of rural areas. many hackerspaces also function as a tool library even if they don’t use the term.

Great suggestion.