lmao
That's some dedication. But Valve successfully made the transition to becoming a platform. I don't think they want to go back to game dev.
Half-life Alyx came out 2 years ago.
Aperture Desk Job came out about 7 weeks ago.
Artifact came out in 2018
Dota Underlords came out in 2019
Alyx came out in 2020
smaller projects like Aperture Desk Job (like you mentioned) and The Lab exist.
Artifact's 2.0 beta that became Artifact Foundry came out in 2020, but had the plug pulled on it and went free to play on Steam, as well as the original giving you all the cards and being free to play as Artifact Classic. (The original Artifact was good, and I stand by that fact)
CSGO and Dota 2 still get updates.
I never understand this "Valve doesn't develop games" narrative. Sure, you might not have liked Artifact or Dota Underlords, but they're still games.
Plus I think if you played Alyx, you probably know that they are seem serious about Half-Life's future.