I almost always choose to play as a boy, except for when I really like the design of the girl protagonist. I'm playing through Legends Arceus right now and I chose the girl because I thought her design was cute. (Unfortunately, this also means that the NPCs refer to me as she/her, but I've managed to separate myself from the protagonist by giving her a different name and making her a personality in my head for when I'm playing.)

In general, I don't struggle too much when I have to play as a girl, but I still prefer to play as a male character when given the choice. The power of waifuism can override this, though. Ganyu supremacy.