I wouldn't be so optimistic. The Labour parliamentary majority may be very large, but the electoral majority is thin, and in many constituencies Labour only won because reform took votes from the tories. A suitably lunatic tory leader may bring the fascist vote back. This is a distinct possibility for the next general election. Unfortunately Starmer and Co seem to be ignoring it.
It doesn't need the fascist vote back to bring back a Tory government anymore than it needed the Trotskyists vote to get Labour into power. What wins elections is desire on the part of the masses to get away from a hopeless government and promises of a better tomorrow (even without details or concrete aims).
Saying Badenoch will see the end of Tory chances is just wishful thinking and she stands just as much chance of leading the Tories to victory as Starmer had when he took over of gaining such a huge majority (assuming she is still leader at the next election), or Trump had when he first announced his aim to be President.
Politics is far less predictable, in terms of outcomes, than it was in the good old days and, sadly, an element of populism is needed to win elections.