Well, of course the EU chose to be dicks about it - the various UK governments did all their best to ensure an as-chaotic-as-possible Brexit, constantly derailing discussions, even risking setting the Northern Ireland civil war alight again and demand that the EU concede to prevent that.
It was dumb enough that Brexit happened in the first place (some say, the vote was close enough that Russian propaganda made the key difference), but the way that Cameron, May, Johnson, Truss and now Sunak have handled Brexit made an already bad situation even worse. Had they shown even the slightest bit of respect and solution-oriented thinking towards the EU, the EU negotiators would have been far more interested in solutions that don't mess up stuff too much.