While they are certainly more than welcome to make lesser versions of magic items if they so desire, the Headband of Intellect and similar magic items are, RAW, uncommon magic items which actually makes them suited for Tier 1 characters (level 1-4) as printed.
That's fair. I suppose I just don't like the combination of its power, set location, and ease of acquiring. In a typical campaign, you might get a Headband of Intellect at levels 1-4 (likely 4), but it'll be a treasure that you as players can't plan for. It also seems pretty easy to get in BG3; you find some trolls in a house and if you defeat them you get it. It's not at the end of a dungeon or a reward for a difficult quest or anything. All this combined just makes it seem too easy to plan a character around it and then easily acquire the item imo.
All this said, I'm not hugely opposed to it setting Int to 18; I'm just not going to argue for changing it back from 17 to 18. And as @Tuco said, Int of 18 isn't overwhelmingly powerful, even for Int spellcasters.
And frankly 17 as a odd number makes this item considerably less appealing. For all intents and purposes 17 is pretty much as good as 16, outside of few fringe scenarios.
Less fringe since this campaign seems to revolve around Mind Flayers, although this heavily depends on if Larian will give Intellect Devourers their signature ability. Having a 17 in intelligence is definitely better than 16 when it comes to rolling 3d6 and comparing it against your Int Score to see if you lose all your intelligence.
