I'm assuming you're talking about the tactics rather than the corruption there...
But it's definitely where other parties on the left need to improve - winning election. Don't bother with careful policy decisions and detail, just get a couple of catchy slogans and headliners, stick to campaigning on those and total ignore any other questions. Johnson got away with it just by repeating Get Brexit Done to everything. Education, health and care service, defence - didn't matter. just turn it onto Get brexit Done.
Other thing they need to do is kick the Tories when they've got something on them and keep kicking them like the Tories did with anti-Semitism. Or save it to the very end of the campaign and just hit the electorate with a barrage of misdeeds. Or the Hillary Clinton strategy as I call it. The anti-Semitism/Islamophobia report that never happened, the corruption on govt contracts, letting Cummings get away with crap, Windrush and PritiPatel, even Johnson's personal life (though that would prob have to be done more slyly via the Twitterati due to potentially legal ramifications.
Trouble is Starmer isn't a guy to do that. He's strait-laced and about as charismatic as wet lettuce. I like him - I think he'd be extremely capable as PM - but he doesn't have it in him to win the election, especially against the shithousery that the Tories would get down to.