My second playthrough, I know that the Headband of Intellect exists, so I make a Rogue (Arcane Trickster) or Fighter (Eldritch Knight) and dump INT, allowing me to raise other ability scores that would never otherwise do.
That's precisely the problem imo.
Player 1 plays a Githyanki Eldritch Knight and puts points into 16 Strength and Intelligence, taking advantage of the matching racial stat bonuses.
Player 2 plays a Dwarf Eldritch Knight, dumps Intelligence to 8, has 17 Str and 17 Con, and gets to sprinkle the remaining points from the Int dump into wherever. Then, with Headband of Int, also surpasses the Gith in Intelligence and spellcasting.
Or they both end up wearing a Headband of Intellect and it's a tie in spite of the Gith having a natural 16 Int. Except the Dwarf has much higher stats elsewhere.
It's like you're actually being punished by making a "good" build and not building around one particular magic item. The only somewhat redeeming factor could be that there will be much better helmets or headbands, and NO Super Headband of 20 Intelligence. Still, if I would make a more offensive EK spellcaster, I would still prefer a Headband that would +2 the Gith's Int so it would
matter that I made them smart to begin with.