If ever there was a justified case for sending a machine to the landfill, this one seems like a good candidate.
Why would you even want to use such a terrible machine? Is it nostalgia, ideals, masochism, a weird fetish, or something else? It definitely isn't money, as you can find something much better by going dumpster diving.
It depends. Spend enough time on bug trackers and forums for open source software, and you're bound to encounter hostile assholes shitting on devs when they make decisions to drop support for ancient hardware like the OP. It's particularly egregious IMO because they usually are willing and happy to use an ancient build of some proprietary software without complaining, but feel entitled to demand more from open source maintainers for some reason.
If you're doing it for your own fun, not making demands of devs/maintainers, and accepting that you're not going to get support for a lot of software, then it's all good.