Hey thanks for describing this hypothetical situation, I pay Steam for a lot of game licenses so I’ve lost touch with the current philosophy of hypothetical alternatives.

I’m considering moving to Debian Stable plus Flathub for graphical desktop packages like Firefox, it works well on the Steam Deck. SteamOS also provides Distrobox which helps in some cases.

Upvote for calling out the ambiguity in the title:

• “Doom popularized some mechanics still used today” - this is not that.
• “FPS engines descend from ideas in the Doom source code” - this is not that.
• “id named their engines with ‘Tech’” - this isn’t that, Doom was before that.
• “Modern descendants of the original Doom engine can informally be called ‘tech’” - this is what the title means.

Best adventure game ever