Ehhhhhh.... I don't actually think a five year limit applies much at all. A lot of the current/past "top" creators have been making online content for a long time before ever making it big, and have managed to maintain a decent following even after their "peak". Just throwing the first normie creators I can think of at a wall and seeing what sticks:The five years thing usually applies in terms of being "big" (Boogie fat joke here), trends change, tastes change, most people have a drop-off. The difference is whether they're willing to accept that.
Some people can let their careers grow old with grace, they'll save money when they're doing well so that years later they can keep posting videos for an audience that's a quarter of the size it used to be while being satisfied and financially stable doing so.
Others indulge in instant gratification, like Boogie/DSP, etc., and become more and more desperate to maintain that lifestyle even when their income is a fraction of what it used to be. They're the ones you see sulking and begging to a point where they alienate all their fans, rather than just the tourists who've moved on organically.
Jerma? Around for a long ass time as a TF2 youtuber, then transitioned to twitch to do gaming streams, then started switching it up to surrealist skit streams, now retiring after around 15 years of content creation. A lot of TFTubers have made the transition to normie streamer, RTGame is also quite large and has been around a long time.
Assmongold? Around for a long time as an MMO femboy, now does react content? I don't know since I don't watch him, but he's been around a long ass time and has more fans now than he ever has.
That Ninja guy was around for a long time as an esports femboy before streaming, then he streamed for 5+ years before he took off.
Pretty sure Ludwig was around for a long ass time before getting popular too.
uhhhhhhh I don't know what normies watch tbh I ran out of steam after mentioning TFTubers