I've helped my sports teacher at school when I was still there(ow that was 10 years or so ago) a few times getting something like 25e/whatever I was doing at the time(even post-chool I helped him a couple of times) and the guy voluntarily paid I didn't expect anything in return. As it was mostly staring at a reinstall most of the time it wasn't an issue. Beyond that helped fix something for a neighbour once but gotten no other unsolicited requests. My phone number is for my friends and family to contact me and nobody and I mean nobody else has it, especially work.
But yeah the bring it to me and I'll take a look approach definitely helps filter out those that just want some free help vs those that actually need help to fix it. We have an electrician in the building and he's a damn good one. But always when we ask him to help(not questions but actual work) we ask him how much we owe. Usually he won't charge much else but materials but I am always willing to pay him for any work.
Usually I don't get requests from coworkers about fixing their kit(other than during work hours and if they're lucky I'll have some time to do it) and my friends mostly have a clue what they're doing so yeah. Wouldn't be all bad to have a bit of extra work like this but as I haven't been using windows for over 10 years in anything other than professional - figure it out and get on with whatever you were doing - capacity I probably wouldn't be good at any such work anymore.