I would argue that any party is a more serious option than red or blue

Not if they don’t stand the remotest chance in hell of winning.

All it takes for a party to get traction and votes is popularity

Oh, is that it?

and popularity can be farmed in a day

Ok, you’re just delusional.

if a bunch of famous people with millions of followers would start advocating for a third party

Hey, it’s like if every single worker in this country agreed to take part in a national strike, then worker’s demands would be met the next day. Oh wait, that’s a fantasy scenario that will never happen.