It's so sad. I queued up at the Immigration Office the other week to collect our new residence cards (specifically for Brits who've retained their rights to stay), and it really brought it home that if you're British, you're now no different than any other non-European. We have the cards and the right to stay, but we're out of the club.
Of course, if you're determined to remain in a European country and are happy to pay your way as a British immigrant it's possible to do that, as we have - but for many who just enjoyed the freedom of movement bit with no ties or checks, that's no longer possible. As you'll know, it's not cheap or easy to take residency. I doubt we'd have done it if not for Brexit, for years we were happy doing three months here and three back in the UK, rinse and repeat. Now we have no intention of returning to live in the UK, even though we have a small property there (our fallback in case everything somehow goes pear-shaped).