I think about the 5 games for $5 bundles with amazing indie games whenever this comes up.
You can still get deals like that from Humble, Fanatical, and a few others, but nothing like that on Steam anymore. I don't really understand why people buy so many games on Steam, tbh. 90% of my game purchases are bundles.
Then again, I'm a very patient gamer who prefers short and targeted indie games to AAA games, so that's probably most of the answer. I'm cool waiting 5 years for a game to be cheap. I have literally thousands of games I would be interested in playing sometime, so it's only the very rare game that I'll buy the year it's released.