I was thinking about this question today as someone used our work printer for some personal stuff.
As for me, I am printing little things that I would say make it worth it. I’ve printed lens adapters for my camera for example. That’s worth a good 14 to 30 bucks per print. My most favorite photo was with an adapted lens that came from a projector. I also printed IEMs and those things are worth it. Listening to music is second to none on those things. Plus I printed the same shell but for ear protection and again the fit is perfect and sure there’s post processing to get smooth surfaces but in the end it looks like a professional made it. So I think 3d printers are worth it.
Definitely worth it. Sometimes I make little things, like I got a new tool that has a difficult adjustment, but printing a knob made it comfortable to use. I got a new phone last week and couldn’t find a rubberized case I liked, so I designed and printed one this weekend which fits snugly and provides a much better grip. I’ve made cases for other projects, even built a weather station. The biggest project I’ve done is a star tracker (OpenAstroTech) which holds my camera, most recently used during the eclipse in April. Sometimes my printer may sit idle for almost a year, sometimes it prints constantly for several weeks, but it is a very useful tool worthy of a permanent location on my workbench.