It’s entirely possible that every anti-Farage voter could coalesce behind him. Upon winning, he would have his name and face be publicly known. He would attract a huge amount of (global, even) media attention. He would suddenly have a serious job with real responsibilities. And he would have the unbridled rage of everyone in the UK who has decided that 100 years of the Tory/Labour cycle has run its course and meaningful change is needed. To give an indication of the electoral weather, Reform UK has led the national opinion polls for more than a year.
I’m not sure he has the balls for all that, but we will see.