People said the same thing about David Cameron is his first term too though. No enthusiasm for him, couldn't even win a majority, and then romped to victory in the second term after being told that UKIP were coming for all his votes.
I wonder if there are still enough people who vote Labour and Conservative no matter what that despite the polling, Reform will never be able to make up the numbers from the people who don't. Labour have never got less than 8 million votes (at least since the 80s) and the Tories 6.8m at the last election was their worst performance ever, but typically they also never drop below 8 million. You've got to wonder how many votes Reform can genuinely steal from these two parties, bearing in mind that they're unlikely to capture many from the Lib Dems, SNP, the Greens or Plaid Cymru. They basically need to double their vote to match the worst performances of the big two parties, and there is a sizeable number of people who always vote for the same party, or like their local MP regardless of their party. In theory, it's possible. Around 30 million people usually vote, so if Labour and the Tories collapse and get around 14 million between them, then a lower number could win a General Election, but that's assuming that such a collapse would all move to Reform rather than the other options.