The problem in the UK is that Parliament and the government are trying to deal with a set of circumstances they're not used to handling.
Britain's relationship with the EU is not, or was not at least, a matter of contention between the two main parties, so much as an internal dispute in both of them, but primarily among the Conservatives. Nor was it one, at least until 2016, which particularly interested most voters. It rarely made the top 10, if that, of voters' concerns in opinion polls.
David Cameron's ill-conceived referendum was intended to put an end to the fight within his own party (ha! ha!) but resulted in a situation where many MPs on both sides of the political divide and the argument about Brexit found themselves at odds, variously, with their party's policy, the majority of people in their constituency who voted in the referendum, their local party and party activists, and their local voters.
This puts tremendous stresses on the parliamentary system, which hasn't really had to handle this kind of thing in the past, and then Theresa May has further confounded the mess by, after her ill-judged snap election, trying to behave as if her minority government enjoyed the crushing majority she expected to win, and generally ignoring parliament as much as possible. As I understand it, Labour have never had any approaches, formal or informal, from the Conservative front bench to try to explore some sort of bipartisan compromise they could both live with, despite the fact that it's been clear for a long time that there's no obvious majority in parliament either for any particular form of Brexit or for ignoring the referendum and remaining.
Add to this the fact that both the government and opposition front benches are, with some notable exceptions (Keir Starmer in particular), the least competent we've seen in a long time, and we have almost the perfect storm.
Ultimately, in the UK at least -- obviously it's different in the US -- the government derives its authority from Parliament, and I think we're now seeing parliament trying to reassert authority in a situation where the government has pretty much lost any authority it did have.