While I was also part of some niche communities back in the Reddit days, thanks to Lemmy, I switched to Linux and have found interesting new websites, tools and apps. So I'd say overall it's a net positive.
I used to think the same and sure there are still definitely games that won't work, but gaming on Linux has come a loooong way. And with the recent bullshit that Microsoft is pulling with Windows 10 and especially 11 I just couldn't take it anymore.
Read the rest of their posts. It doesn't seem like they're being sarcastic.