What might work is a funded 2 week lockdown of *everything everywhere* no exceptions, with longer quarantines of carers and vulnerable people leading up to that, because its logical that if it can't spread, it can't survive (well, we think..).
But that's about as pie in the sky thinking as saying if only the billionaires distributed their money back into the community noone would be poor.
It aint gonna happen, and if it aint, then we're stuck in this hellish loop forever or until the rich get bored.
And that is the problem. Lockdown isn't a solution, because its only prolonging the inevitable. Govts know this, which is why the vaccines were fast tracked. If they can do the job instead (and they can't for the same reasons - mutations, plus focus only on wealthy countries, and assumptions made about efficacy long term), then we get out of the loop, without looking like were giving up on the idea.
You would need a worldwide effort to make the concept of a lockdown work, which is why till last year none had been attempted on this scale. I think it was widely acknowledged that you could control a town or perhaps a city, but not the world.
And because of all the variables, trying to determine usefulness of national lockdowns is near impossible, scientifically. You know its true, come on, come clean!