It also created a curious effect where a Sinn Fein MP (Gerry Adams), who like all Sinn Fein MPs never took his seat because he would not swear allegiance ot the crown, had to accept a crown job to resign, which David Cameron criticised him for (in rather poor form).
And there is nothing aside form precedent preventing a capricious government from stopping MPs from resigning by refusing to make such an appointment.
It's all fun and games having an unwritten messy constitution until a government exceeds its powers to e.g. prorogue parliament against its will and we have to wait months for a court to rule on it when a proper consitution would never have allowed such an act in the first place.
An insurrection like January 6th would suceed in the UK because there is so much arcane bullshit where our constitution should be, we are solely dependent on the good will and character of the current government to run things as they are meant to be run.