but that difference is still important to a non-insignificant amount of people, and there's nothing stopping the designers putting in the rules 'at 5th level your fighter gets to pick a magic item of X rarity for your character', it's basically already a feature of the artificer even if they have the justification they're making it themselves, i get that some people might not like magic items appearing out of the ether simply because you reached X level but it's better than being subject to GM charity, say your sword was empowered by the stories told of your fighter turning into an icebrand, that your shield evolved from being soaked in the blood of 1000 slain monsters turning it into a +1, the ambient magic was absorbed into your boots and they turned into boots of flying.