Yeah, that's pretty much what happened to me in 2008 with 3.5. There's no problem playing a "dead" game if there was a ton of material produced for it. In this case, 3.5 and PF1e are so close that a lot of the material from both can, with a little bit of fiddling here and there, be cross-compatible, effectively doubling the amount of material available. I mean, you can play that stuff forever.I mean, that's kind of what happened with PF1, which is my "forever game." Paizo stopped supporting it, and when they did a lot of the wider community did too; certainly the OGL debacle didn't help, and nothing has since ameliorated the harm caused by that (since you can't publish PF1 content under the CC, and that's 99% likely to remain true even if WotC ever releases the 3.5 SRD under it).
Yeah, I admit that I don't completely understand the gist of this type of question and many related ones. What would I actually personally do if someone stopped publishing new material? Use the 50+ years of old material, or make up my own. There's so much material out there. I don't really understand the need to be playing whatever's brand new. I only adopted 5e—reluctantly—two years ago when I relocated and joined an existing group that was already playing it. I have little interest in Pathfinder 2e or Remastered except from an academic curiosity standpoint, and I'm mostly only interested in Pathfinder 1e because it's compatible with 3e and I'm willing to finally, grudgingly, admit that it's enough of an improvement to probably justify using it instead of 3.5 if I were to start a new campaign.Pull a Pathfinder and build new worlds with old rules and expand and adapt. Which plenty of GMs do anyways.
You might enjoy this: - I'm only partway through it, so I'm not sure what the conclusion will be, but Bob is usually very, very reasonable with his conclusions. (Although he does like to rib his paizo audience a bit)In fact, given that a lot of the new material (at least for 5e; I know that this isn't the case for Pathfinder) is actually "remastered" old material, new material is especially meh.
Wasn't he a GURPS man?With apologies to Douglas Adams.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.