Voters vote on the basis of what the candidates promise. This may be due to personality, policies, or many other things, including "anyone but (other party who I now can't trust)".
They expect the winning candidates to represent them at the level of government. If they promise certain things in their manifestos that matter here, they will expect them to be prioritised and delivered, and that other things do not get a lot worse by doing that.
Looking at the revolving door of No. 10 Downing Street, people express their frustration with as high a level as they can, if they do not think that their MPs have delivered anything. They have not seen big differences under the largest parties for a while now, so they are giving alternatives much more of a chance.
In Reform's case, Farage is the highest level where they could show their frustration. Clacton could do this on a local level, and in that way, the national level benefits (according to many). But Clacton really does not need to be somewhere where there is a totally unworkable (maybe fantasy) manifesto where a relocated hand dryer or one affordable house is offered in sarcasm, to highlight what the others were not bothered about. Promised through a disguised Oxford Classicist with no political administration experience who claims to be "intergalactic". He does have to be understood and stand up to real life in Government, and in Clacton, if he is elected. He has no further team members, only a newly formed voter tribe.
Recent elections have seen red Lab. strongholds sweep to blue, green, yellow etc, from election to election. Not a small change, a total wipeout. The change in the number of MPs this means, and the revolving door at the level under 'PM' is massive. That is the part that hits people and parties locally.