Look at the graphs below Boris has been way above KS from February to November when you would have thought due to the way people like you think he has handled covid it would have been the other way around, and in the other two the majority don't think Labour are fit to govern and wouldn't trust them with the economy
First thing - I don't in any way think I'm representative of people in this country. I read UKHSA/PHE reports rather than rely on the media's interpretation of them, and have a background in the molecular biology of infectious diseases that means I can read original scientific papers and have a pretty good understanding of them. Most people aren't like that.
Secondly - stuff like "best PM" is an amalgam of a whole bunch of stuff, where "competence" is only a part (compared to eg "likeability"), and the specific details of how one part of the job was handled is an even smaller contributor. And there's tends to be a bias towards the incumbent in these things, as they are generally much better known and can actually "do stuff", whereas all the LOTO can do is criticise.
But this Yougov survey is perhaps more relevant, specifically on how well the government is handling coronavirus, and it looks rather less rosy for Johnson. A brief initial surge of enthusiasm in the early stages of lockdown, another bounce due to the vaccine programme but that's evaporated as first delta and then omicron came along. And Yougov allow you to compare other countries - the UK is quite similar to the US in particular, but a lot of countries have seen this pattern of vaccine boost then delta pessimism to varying degrees and with different timings, but the UK has fewer people thinking their government has done well than most countries.
Yougov also ask the simple question "Thinking about Boris Johnson, do you think he…Competent or incompetent? , to which the answer has been "yes" apart from briefly during the vaccine rollout.