Plus, it doesn't happen much (if ever) that a game gets delisted/removed, but I prefer having a local copy of game files for games I care about rather than trusting remote servers to always have it available.

I hear you. Games preservation is a travesty of greed. I have a folder full of installers for old abandonware in case the publishers decide to revive a franchise and DMCA the sites hosting them.

Though Steam must have a rider in their publishing contract to never be forced to revoke licenses or something, because delisted purchased games remain downloadable even when the game has been completely wiped from existence. They're the one store I trust to not completely screw me over - even GOG has had to remove downloads before.

(On the other hand the way they allow developers to remove demos when the full game comes out is absolutely rage-inducing, but that's a rant for another time...)