"Why Labour was crucified in the polls. Their message did not resonate with voters.
Below some reasons:
Painful for Labour, but sadly all too true.

Why labour lost"

Labour lost partly because the party is a bit shite and inept.
That much is Labour's fault..

But Labour mostly lost because the international populist far right has become too overwhelmingly influential,
attractive, and persuasive for mass 'ordinary' voters..

But why did Boris win...???

We can ask the same question about the rise to power nearly a century ago
of a nasty little Austrian bloke with a funny moustache...!!!

Boris and his backers and advisors certainly learned well from their expensive exclusive public school history lessons...