Lego Harry Potter Years 1-4 and god damn do some of the games mechanics feel archaic af.
Character switching in particular is just not good. You can't switch characters on the fly in free play in the overworld, you have to do it through the golden Polyjuice's, and they are not in every room so you have to constantly backtrack just to switch characters if you didn't bring the right character with the right ability for a puzzle. I know people have said it fits in the context of the world, but it's also a videogame. Just because "it fits" doesn't make it good.
You can tell this is a "older" lego game, despite only being released in 2010.