Very interesting thread, I want to give my two cents.
I grew up with an Atari 2600, then a Commodore 64 and an Amiga 1000 afterwards.
I buy both physical and digital releases for the 2600 and C64, and I would say they have a healthy homebrew production, where you see no less than 20 something new games or hacks per year, with quite a number of those of “commercial” quality and some gems like Draconius on the 2600.
I recently bought an A800XL and have it modded with 1mb ram and dual SID, fixed composite output and SIO2SD. I wanted to try those Activision and Lucas games I love on the C64 that I had heard the Atari version is the best. And also Alternate Reality with music I found amazing being able to upgrade the memory, almost nobody uses hardware improvements in C64 besides selectable kernels.
So I got hold of a games collection and, well, I enjoyed Dropzone, Rescue on Fractalus, Koronis Rift, ... but didn't find many "new" releases I truly enjoyed. It took me a while to find some european website with homebrew releases, some ports like Gunfright or Skool Daze but no recent release with quality similar to the commercial games of the 80s, something I can find for the 2600 and C64.
While the C64 nowadays has a “second life” in terms of gaming, with programmers pushing the machine (the stock machine) to the limits with games like Galencia and Sams Journey and successful campaigns in Kickstarter like Galencia Khaos Sphere or Unknown Realms, the A8, with outstanding hardware capabilities, feels like a less interesting platform.
Then again, maybe I'm terribly lame searching homebrew for Atari 8 bit