Yeah, I mean every single canon and semi-canon installment so far, like the books or shorts, has showcased how utterly shit Anna is with anything to do with royal duties or running the country whatsoever.
It's always Elsa doing paperwork, attending meetings, reading letters and whatnot, being dutiful and responsible, and Anna not simply giving a fuck about anything aside from her own entertainment, and spending time with Elsa. Like one book mentioned she has 1 meeting per day, breakfast with Elsa, and she's consistently late for that - and after that she just amuses herself till Elsa has 1 hour of free time for charades in the evening. Elsa's got this huge workload, and does Anna think to share a bit of the duties? Nope.
In the first movie, she couldn't even be bothered to learn the protocol for her sisters goddamn coronation, and caused a massive scene. When their parents died and Elsa was a shut-in, she apparently didn't suspect that something might be wrong with Elsa and she might need to ascend to the throne and start learning how to do the royal duties and run the country - instead she just went "I'm so bored, I wish I had someone to amuse me".
Like, at least she means well, but she's incredibly, ridiculously underprepared to run a country because she doesn't give a shit about boring duties.
Arendelle's going to go to shit under her. Or then a strong parliament will spring up who'll drastically cut the monarch's power and reduce her to a pretty puppet smiling and waving from a balcony and occasionally giving a speech somewhere, and she'll be relieved that someone else will take care of things.