No idea, but just guessing a large number of the new and past games are games most people never see or ever heard of. They're just on steam. I know steam recomends a small number of games and anything outside that I have to search for because I saw it elsewhere.
Too lazy to check source but a reddit post comparing it sais last year was even lower(9% iirc it said), it is a consistent statistic, a lot of people just don't play the lastest game because of money/sales, because they wait for later versions, because they just play older games or some genres that don't have many releases anyway(4x, RTS, Racing sims etc) and also a non negligible amount are just some form of bots(card farming, those weird games were you can grind NFTs, dota2/cs2 bots and so on). It isn't super surprising although it is an interesting stat imo.
No idea, but just guessing a large number of the new and past games are games most people never see or ever heard of. They're just on steam. I know steam recomends a small number of games and anything outside that I have to search for because I saw it elsewhere.
The stat isn't the % of new games played which is irrelevant when 10s of thousands of AI/asset copy paste slop gets released every year on Steam, but the % of their game time spent on a new(as in released in 2025) game.