I don't know what you expect from hogwarts legacy, but heres my 2 cents.

If you come for a Hogwarts lifesim, a sort of Bully but set in Hogwarts, with the feeling of attending the school and classes, and take part in school life and interacting with other students, dont buy a console for Hogwarts Legacy.
All these parts are severely underdeveloped and dissapointing. While there are many students standing about all the time, you will only interacty with anyone when a quest requires you to. 90% of npcs you will meet twice: when they give you a quest, and a secend time when you return to them to finish the quest.

If you come to Hogwarts Legacy for a decent action game (i wouldnt call it a rpg, there are numbers involved, but they are absolutly meaningless) with huge collections to aquire, and the pretty, Harry Potter flavoured, visuals, then you will have fun with the game. But maybe don't buy a console just for Hogwarts.

I use Android so I can't speak to the Iphone app, but the official android app uses way too much data. Looking at a few posts in the official app uses about 1 gig of my mobile data, while rif uses a few mb, looking at the same few posts.