I feel the same OP. I'm not sure if it's a parallel that will chime with anyone else but I immigrated to the UK 12ish years ago, as a student. The rhetoric quickly morphed around that time, to fears of hordes of illegal immigrants overwhelming the UK, claiming benefits rah rah rah. During this time the UK did no exit checks - ie they had no idea who was still in the country at any given time, who had arrived from outside of it. Tbh I'm not even sure if they do exit checks now. Pretty basic thing, no? If you're stressed about your immigration numbers, use a very simple system to at least attempt to understand and manage information.
Now we come to the pandemic. It's non-stop talk about variants and quarantine, and has been for months. If you arrive to, say, Australia or Israel, quarantine means being taken from your flight to a designated bus and then hotel and staying there until the quarantine period is up. In the UK? Arrive, go through security on your own, and make your own way to wherever you fancy quarantining - feel free to lick the Tube on your way through London, why not - and then quarantine, or not, because let's be honest the chance of anyone checking up on you is pretty minimal. Oh, and we'll be sure to spend an extra few weeks dithering over whether country x represents a threat despite plague-like conditions being reported on international media, give people a good chance to get over here if they'd like.
If overseas variants are seen as a threat/potential threat, let's treat them accordingly.
Useless fuckers.