The same applies to the Tories, despite Badenoch trying to steal Reform's clothes. It is clear that at a time of great dissatisfaction with the government of the country the ruling party will suffer the backlash but at such a time you would normally expect the main opposition to benefit instead of making huge losses to add to those they suffered in the last GE.
The rise of Reform and, to a lesser extent the Greens, plus the nats in Scotland and Wales is not only to do with left or right but more to giving the established parties a kicking. I believe, if you ask those people who have voted for Reform why they did the answer would be "well they can't do any worse" without having a clue what their policies are other than stopping the boats and kicking the unwelcome immigrants out of the country.
Farage receiving a "personal gift" of £5m by the main party donor is apparently less important or "corrupt" than Starmer being given a pair of glasses and a sharp suit according to the MSM.