Wasn't the point that Bran would be the last king? So the monarchy ends with him. But he'll live forever so I guess it's a moot point?
I mean it's still a high council + king except the council voted for the king. Presumably if something happened to Bran they'd just elect a new one. Personally I don't see how this is a significant improvement in any way but the show ends there so it's not explored. If anything I'd look at the rest of the Starks for the point - Jon and Arya both abdicate claims to power to try and live outside the system entirely. But Sansa is just doing the "good monarch" bit but in The North.
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I definitely did not forget to put the 2020 GOTD Guru winner, azuarc in my sig!