I'm not really sure this is as widely applicable as you seem to think it is is the thing. Air Domes on your body might be decent against very precise beam attacks but anything with a blast radius or an AOE wider than the dome is going to be a major issue. Even blocking 100% of your body from one side isn't going to help you much if the fireball explodes into a zone-wide inferno, or if the water dragon bullet snakes around to hit you, or if the earth jutsu is something like spine of the earth and errupts from beneath you, or if turbulence from the wind jutsu rips you off of the Air Dome, or....
Like, there are a very wide variety of use cases here where this won't end up being pretty. On average, it defends against piercing and bludgeoning from projectiles and limbs very well, but anything that has more of an AOE damage effect --even explosives attached to kunai that ping off the Air Dome-- might catch you in the blast radius and seriously fuck you up.
Armor in universe is pretty much useful IFF it offers full body coverage and doesn't decrease your ability to dodge against things that it won't defend well against. Even some of our best armor jutsu straight up isn't good to use against esoteric damage types. For all we meme about "Unstoppable PEA 30 combat god rawr unkillable!", a single hugefuck fireball could still send us on a one way trip to the Pure Lands because no armor we've seen does jack to protect you against being engulfed by fire (with the possible exception of something like Hozuki's Mantle at the right angle, but that has other massive drawbacks. You get what I mean.)