You'd be surprised to find most studios pick X over Y because it's either familiar to their devs or cheaper. Better doesn't really play into it and a thorough evaluation beforehand isn't usually done.
As former IGDA member no wouldn't, however most of studios don't pick a raw graphics C library versus proper engine, unless its their first title and don't have any clue about the games industry.
Funny enough, during my 30 years (give or take) career I have seen many more game projects fail using Unity than projects using cobbled together inhouse engines. It's always the team that counts, not the technology (the technology just always gets blamed when the team fails to deliver, the actual reason is usually organizational).