well no, steam has let in developers who clearly stole games: https://gamerant.com/biohazard-village-copycat-game-removed-steam/
There is also the problem with steamworks, it allows anyone to kick anyone: https://www.shacknews.com/article/100567/locked-out-was-sickbrick-stolen-from-it...
clear cut case of stolen RPG Makers: https://techraptor.net/gaming/news/steamwatch-steam-developer-called-out-by-comm...
Copy cats: https://screenrant.com/among-us-most-obvious-clone-pretend-steam/
Lets developers lie: https://www.destructoid.com/the-war-z-launches-on-steam-amid-accusations-of-frau...
Valve removes anyone game however they want: http://angryjoeshow.com/ajsa/forums/topic/23557-ride-to-hell-retribution-finally...
you can ask the developer of this game, his game got removed because Valve thinks its a porn game: https://seeminglypointless.itch.io/18orolder
So no Valve doesnt do a better job or "higher barrier", the money to pay the $100 is either stolen or easy for them to get because they are scammers. It is also note that Valve does not check the bank or documentations, any scammer removed can easy come back with the same or fake documents.