I do notice that when things go wrong, Boris is blamed singularly and its personal. When things go right it is a joint effort...
That depends of the degree of involvement elsewhere. For instance, on repeated failures to lock-down in a timely and comprehensive fashion, I do blame the prime minister. That's his call, albeit in concert with his scientific advisors. Even then I sense there were tensions involved.
To get that wrong the first time was poor judgement, but we can perhaps afford some leeway due to lack of knowledge and the novel nature of the pandemic. To make that same bad call repeatedly is a different matter. It's a singular judgement call and it's on the prime minister.
The decisions over vaccine procurement may have been made by the prime minister. If he got this right we should duly afford credit, but it's an enormous logistical exercise involving countless parties and bodies, all of which had to play a part. Widespread congratulation therefore seems appropriate.
I'm not making this distinction because I want to be awkward. I'm making this distinction because that's my understanding of how these different aspects of the pandemic response were organised and played out.