Coming along with getting old is having more things to do instead of video games, like side projects, or board games, or hanging out in person. Personally, starting ~3 years ago much of my video game time started getting replaced with tabletop RPG's as a way to spend time with friends, even online ones. I hadn't ever played tabletop RPG's before that point.
So when several of these games came announced as "not on Steam", my reaction was also "it's ok I can wait."
Luckily my computer gaming friends still have time for a match here and there, and games that are part of series we really enjoyed(like Borderlands, or Diablo though that franchise doesn't really grab us the way it used to) can usually bring a few of us together at odd times in the evenings. And double luckily my wife loves Rocket League and we usually squeeze a few matches in before we wind down for the evening.
All my friends and I (30+ crowd) are like "fuck that, I got other shit to play" for Borderlands 3 but we all grudgingly used Steam back when CS:Source came out. I wonder if it's an age thing. I know my backlog is years long as this point so waiting 6 months to play it isn't making me lose sleep.