In my case, I had Photoshop CS3 and kept it running through MacOS Sierra by just using the Migration Assistant when I got a new computer. When I finally upgraded to Catalina, that wasn't an option anymore since it was 32-bit. I picked up a copy of Photoshop Elements during a sale for cheap, but wasn't at all happy with that. Old versions of Elements were exactly the same as the full Photoshop version, just missing a few advanced features that I didn't really need. But the new version of Elements was terrible, with a dumbed-down tabbed user interface.
In the end, I gave up and subscribed to the Adobe Photography Plan which included Photoshop and Lightroom for $10/mo. I don't like subscriptions, but this seemed pretty reasonable. Looking just now, that plan now costs $20/mo! Yet, I'm still only being billed $10. This has me wondering whether my $10 subscription is "grandfathered" at that rate, or if it will go up to $20 at renewal time!