"No PM since 1945 has been in as bad a place after 12 months"
Off the top of my head:
Sunak - it was already looking inevitable he was going to lose the election although you could argue he inherited the role when they were already doomed
Truss didn't get close to a year to be judged
May - called an unnecessary election, lost her majority and had to rely on loons in the DUP
Possibly Brown although had he called a GE in his first year he may have won Labour another term before the GFC
Undecided on Johnson, he still had some popularity and had 'got Brexit done' which was his first and pretty much only policy. It's hard to judge anyone with the pandemic playing such a part soon after he was elected. It was probably just over a year before his behaviour started catching up on him.
So I make that virtually very PM of this century other than Blair and Cameron (and possibly Johnson).