Can't see how this means much. He clearly can't explain precisely why he isn't going to be in a position to impose a lockdown even if he wanted to.
I'm not a fan of Johnson's, but even I get why the PM couldn't realistically be expected to state that his own MPs would boot him out if he tried it and due entirely to his own arrogance and stupidity he lacks the moral authority to bring the general public with him. Of course he just gave a politician's answer instead, what else was he going to do? It's a fuss being kicked up about not much.
Also yes, I know some of MN find it very hard to get your heads round this, but large swathes of the population can absolutely choose whether to comply with lots of the lockdown rules. Obviously nobody can go to places that are shut, but what we can do is socialise in private homes, and actually outside in public in larger groups than permitted tbh, I did plenty of that last time. We can also use businesses that remain open illegally like hairdressers, personal grooming services and pubs doing lock ins. There was plenty of that about last time. There simply aren't enough police to prevent it.
It's also the case that if people want to talk about the possibility of deadlier variants, vaccine resistance etc, rather than based on how we've seen Covid 19 play out so far, then they also need to consider how the factors that allowed previous lockdowns would still be in place. The 2020 and 2021 lockdowns required a cohort of people to do work outside the home to keep society functioning, and a lot of people who weren't in that category to be willing to stay at home out of trouble. If we suddenly got a much deadlier variant, neither of those things can be assumed.