Well, usually people find 2 to be the hardest to get into so that’s interesting!
I find 3 to be the easiest to understand, and it actually has proper tutorials which can be accessed at any time, unlike XB2 (core bursts in battle are like, never explained!).
My daughter (12) recently finished XB3 and loved it, but is having trouble with the battles and systems in 2 - especially the forced field skills. Xenoblade 3 never locks anything away behind skills, aside from the ladders, ropes and slopes which just require a simple chat to the relevant hero once to access them you’re able to use them going forward.
I do get that XB3 can be overwhelming. 7 party members at once is a bit of a jump up from only 3. Not for everyone!