It's all about taking the Tories further to the Right. They saw how the strategy worked with UKIP. They know Labour will have a mess to sort and won't be in power for ever regardless.
You'd think they would be happy with how far to the Right they have pushed the Tories already, but no these people are never satisfied, nor reflective on how their ideology leads to terrible things.
UKIP obviously were effectively a one policy party, Reform can't be that and that's where they will hopefully find trouble gaining any real support above 10%, and hopefully single figure % which will be an optic to keep them as a minority fringe party. at the next election Enough to fragment the Tory vote, but not enough to gain any heavy traction, because this is effectively how the Nazi's started, as a reformist party to bring down the old parties.
I expect that when Labour get in Richard Tice and bunch of b'stards will bombard media on their perceived failures. It will be a constant, death by a thousand cuts approach, heavily funded, and relentless, in an attempt to discredit them, blame them for the mess the Tories have made, and gain more traction. Labour have to be ready for that and have a good PR campaign, pay investigative journalists to understand how they work, and what they are doing and discredit them. We can't ignore Reform, and for all I hate the Tories, we have to hope they get enough act together enough to keep the moderate right from moving to reform.