I'm not yet thinking that asking the public to wear masks is creeping back towards lockdown: I think that's how it should have been before, that we were "asked" to wear them, not mandated in law. But I'm keeping a sharp look-out for other "controls" being brought back in, by stealth. The original mask mandate was a screeching U-turn from "masks are worse than useless", and I wonder if it was one way that the government tried to make easing lockdown more politically acceptable, since they knew that they would have to do so eventually, but their campaign of fear had worked too well: the public were so terrified, that many of them wanted lockdown and furlough to continue for ever (Mumsnet was living proof of this), so they thought "let's compromise and make the public wear masks, and keep our fingers crossed that we can then ease lockdown".
I do think that as far the government was concerned (and not just ours), mandating masks had little to do with controlling the virus, and everything to do with controlling the public. It was an easy way to make it appear that the government was doing something, with the useful by-product of a very prominent visual symbol screaming "there is a pandemic!", in case people forgot this, and an easy way to spot people who didn't believe in it. By all accounts, Boris Johnson kept "forgetting" his mask when doing his public strutting through hospitals etc, and his handlers had to remind him of his "duty" to wear one by showing him a montage of world leaders, all wearing one, followed by photos od him not wearing one.
Yes, I am deeply, deeply cynical, and not ashamed of it at all.