It is better to have scrutiny in government - even if it isn't quite as agile.
You can still have scrutiny with agility. That is in fact what I am suggesting.
Firstly, parliament is not unicameral, because of the House of Lords. However, the Lords has a definitively subordinate position relative to the Commons, set down in law and procedure; it's used to do largely non-partisan technical work, like originate boring uncontroversial government bills (like the Air Traffic Management and Unmanned Aircraft Bill [1]), and improve bills from the Commons (it's sometimes called "the revising chamber" [2]). They can't block money bills, and they can only delay other bills [3]. So it's not exactly bicameral, either. Sort of sesquicameral.
Secondly, it's not clear snap elections are actually helpful, because if you need a majority to call one, they will be only be called when the party with the majority thinks it can win an even bigger majority. They certainly aren't a mechanism for correcting a drift between the government public consensus. They were seen as sufficiently antidemocratic that the UK sort of got rid of them, fixing the term of parliaments [4], but it hasn't entirely worked, because the one time a government wanted a snap election, the opposition agreed to it (and then lost by a small landslide!).
Thirdly, the queen doesn't decide deadlocks between the public and parliament. The queen doesn't decide anything - she deterministically follows the advice of her prime minister, because she knows that if she didn't, parliament would finish what Cromwell started. Furthermore the idea of "the public and the parliament [being] in disagreement about whether to call elections" is nonsensical, because that's something that is entirely parliament's decision. Perhaps you think she would take a more active role during a constitutional crisis; i rather doubt that, especially after what happened last time the crown did that [5].
[1] https://services.parliament.uk/Bills/2019-21/airtrafficmanag...
[2] https://publications.parliament.uk/pa/cm201719/cmselect/cmpu...
[3] https://en.wikipedia.org/wiki/Parliament_Acts_1911_and_1949
[4] https://en.wikipedia.org/wiki/Fixed-term_Parliaments_Act_201...
[5] https://en.wikipedia.org/wiki/1975_Australian_constitutional...
it's because it's incredibly difficult to get anything passed, the US legislative system has too many checks and balances. Every "check and balance" is another group that has to reach consensus for a proposed action and another point for an adversarial opponent to grind everything to a halt.
I contend that it is better to have a government that can reach consensus easily and act, and that is easy to change if they no longer reflect public consensus, than to have "checks and balances" where absolutely 100% of the government needs to be in consensus to do anything. Gridlock should not be a design feature of a government but that's how the system was engineered (deliberately - it dates from a time when states didn't view themselves as federal subjects but independent states, and this was supposed to help get everyone on board that "no, really, we're just going to do the things that absolutely everyone agrees on", there were many groups who were afraid of being steamrollered without their own special little body and checks on other authorities).
Unicameral parliamentary systems are better - one house to pass legislation, one PM who is a member of the majority in parliament, so everyone is on the same page. Snap elections if they do something that nobody likes, if they don't want to listen to the public then the queen can dissolve parliament and call for new elections.
(the queen actually is a very interesting role in the UK, she is kind of an "oracle" that decides deadlocks between the public and the parliament. When the two are in disagreement about whether to call elections she can resolve the stalemate. She really doesn't do much normally but in times of constitutional crisis can serve as a trusted independent authority - a very interesting safety mechanism that evolved almost by accident.)