To use your extreme example: By level 4, any group with four players could throw together their stuff, sell it all, get a candle of invocation and start chain-gating efreeti. They don't, because it's stupid. Broken elements are only broken if you use them, and if you have access to strong, but non-broken stuff to use instead, your a-ok. It's only the classes for which this middle ground doesn't exist that suffer, and the Artificer doesn't belong to them. He can be firmly within the middle ground if he focuses on strong, but non-broken stuff - just like a level 9 wizard doesn't automatically break the game by his potential to chain bind, or a level 5 wizard doesn't automatically break the game by his potential to abuse explosive runes (note that this is one trick where I'm rather sure it doesn't work, but it still is occasionally mentioned).
(As a reminder, I was answering to this argument by Frank initially:
An actual Artificer is a very weak character. Sure, you can masturbate to how awesome it would be to mix Wizard and Cleric spells, but it really isn't. The Artificer has to spend days of downtime and mountains of gold, and at the end all he gets is a couple of fucking wands. Wizards actually know more different spells than an Artificer can make scrolls or wands of, and Wizards can make scrolls and wands too. In all the literally years of fappery to mystic theurges, geomancers, and true necromancers, no one has ever come up with a single combo that particularly meaningfully benefits from cherry picking spells off of the Wizard and Cleric lists. It's just not important.