For reference what Linus said, in an interview with GamersNexus, was that new writers (i.e. people that were expected to be on-screen) went through probation and an on-boarding process. They would start by writing scripts which would then be critiqued and revised together with the lead writer, if the idea was good enough the writer would then sit down and review it with Linus. They didn't have an expectation that the first few scripts would make it to videos, but expected to see progression. Their on-screen presence would start with appearing in the background of videos, progress to cameo speaking appearances, then larger speaking parts, "unboxing" or "tech news" type videos on a secondary channel or "behind the scenes" videos on floatplane, then co-hosting main channel videos, then finally solo-hosting main channel videos. They expected this process to take 12-18 months, minimum. This long burn-in period was critical to both get the new host used to the audience, and the audience used to the new host.
I.e. LTT has continual growth because it is run by professionals not sometime funny local dipshits with no or limited experience and crippling emotional defects.