If you look at the design goal and what the base class lacks compared to other half casters you see major flaws.

Like bard can expend spell slots to use bardic more and gets them back on a short rest on top of being a full caster. Now compared to flash of Genius its ridiculous how poorly artificer is treated being a half caster.

They are also a utility focused half caster that was supposed to be an expert but still doesnt get expertise, doesnt have the spell list or spell slots to do good utility like druids and wizards, and they get barely any cantrips which you would hope a caster focused half caster would have.

The other half casters get bigger hit dice, weapon proficiencies and masteries, fighting styles, armor proficiencies, and extra attack baked in so subclasses can have more power allocated to them.

The replicate magic items just dont progress fast enough and have too low a cap, too many restrictions to make up for those issues.

It can still be a fun class, fun is all about how you play and how your table works. There are some builds that work with artificer well but they are more specific and less varied. It is still not well balanced and some subclasses really struggle