The Difference is a full on artificer can attack with +10 70 times a session
I'm assuming you mean "scene" rather than "session."
No one is arguing that artificers can't do one thing very well, over and over. My point is that wizards can do that one thing as well, if not better, and in addition they can do many other things and they can usually do so often enough per scene to get the job done. An artificer with a Weapon:10 whatever isn't terrifying.
Also, if we're assuming that you're using 20+ magic item slots for frequency of use on a single item bear in mind that the item will scale up in size. If you're talking about a single 30 enchanted item slot item that is 5 size "levels" above the 9-12 category of basketball or staff. The size categories go from ring to fist to basketball. Let's be generous, and assume that the item simply doubles in size from one category to the next. A regulation basketball is 29.5 inches in circumference. Double that five times, and you get 944 inches, or 78.67 feet in circumference, or 36.73 feet in diameter. So yes, your artificer can do Weapon:10 damage many, many times per day, provided no one minds him driving around in his enchanted tank.
edit: Actually, an M1A2 is only 27 x 12 x 8, so a volume of 2592 cubic feet to the 11695 volume of our magical blaster. Maybe Tankebago? Nope, they're smaller than the tank...
This is moving into HMS Blasting Rod territory.