So I'll say two things to that:

1) If your car is stolen, suddenly none of this capability exists, or is inaccessible to police for some reason. No one can actually just type in your reg and see where it was last seen, seemingly, even though it would be an easy way to locate criminals. And if you think well, thieves will just change the plates - no, stolen vehicles are frequently recovered on their original plates.

2) I keep saying various FB Police pages posting "we found this car X without MOT or tax, last time it was taxed in 2023!" so like...it's been driving for 3 years without anyone noticing? What are all those ANPR cameras for then??

This is the police "prioritising".

Regarding your second point, I don't think you'd go scotch free but the police wouldn't bother coming to the registered keeper's address and attempt to seize the car. I believe you'd simply get automatic fines for no MOT or no insurance (plus penalty points).

So that's that as long as you don't tweet tendencious things because then they might send several cars to arrest you /s