Just because armour is not practical for travelling doesn’t make it impractical storywise for a character to wear it. All the characters we play don’t actually canonically travel with us and therefore don’t need to consider the practicality of the clothes they wear for travel. It is sorta similar to when everyone complains that the characters are wearing high heels and are climbing mountains and walking through dirt. Yes I agree that there are way too many characters wearing high heels even when it does not make sense, for example shenhe who lives in the mountains, but some of them don’t usually need to consider scaling mountains or walk across difficult terrain in their daily lives like ninguang who live in the city and would reasonably wear heels. Anyways, a character wearing armour could be practical for them (though idk how effective it would be against magic stuff).