Also, sometimes you need to first be a bit inefficient and lax in order to later come up with really good ideas and solutions.

IMO it’s really hard to argue with the quality valve software is putting out. I can’t really name a game that isn’t considered a must play that they’ve made

I too thought Ricochet was a blast and an underrated must play. There are dozens of us!

Artifact flopped really hard.

Dota Underlords wasn't exactly a success either.

It's only hard to argue because that's a purely subjective opinion.

how do you come up to this conclusion? Valve has by far the most revenue by employee from all the big players. They seem to be the most efficient at what they do.

They hold a valuable resource developed from prior years of hard work. See also Google search.

Do you think Valve was operating this way when they were trying to make their first money on half-life?