I'd state that the Elemental Blaster line (or maxed out, the Arcana) is incredibly strong for any gunslinger. It is supereffective against two out of three turrets, has high dps, doesn't mess around with statuses (making it effective everywhere), and quite frankly looks cool.
I wish more people realized how awesome this weapon is.
You are right that elemental guns have a disproportionate advantage against turrets. There is some debate to be had, about how status compares to extra damage.
Arcana doesn't have especially high DPS in any comparison I've ever seen. For regular attacks by skilled players (on decent Internet connections), drivers deliver huge DPS. For charge attacks, needle guns and Magnus-style guns do colossal damage. And I'm ignoring mixmasters.
5* Blasters ('cept Valiance, except maybe vs Tortodrones) have the highest reliable DPS of any run-&-gun option, save orbital guns. They also have some of the furthest range, beat just slightly by Antiguas... and *technically* by Pulsars, though that extra range sure won't help you reach your target after the first couple shots push it a mile away.
The ricochets from Alchemers do have the potential to cause a much higher DPS, but even pixel-perfect shots aren't guaranteed to make them land thanks to RNG. Some say to get up close with Alchemers to increase hit chance, but at that point you also have to contend with swords since you're in melee range.
Blasters have an excellent balance of DPS, range and fire rate - all while providing the highest mobility a gun can have. Even orbital guns have their weaknesses in comparison - a slightly shorter range, slower projectiles, and the wide flight path makes thread-the-needle shots impossible.
why use a blaster when you can do the same thing and more with winbillion
The Arcana is good, but not for gunners. A dedicated gunner has multiple guns and the Blaster line does not see as much improvement in DPS from switch shooting as other guns. Where Blasters really shine is as the sidearm of a non-gunner. If you are only carrying one gun, then switch shooting is irrelevant. I would say the Arcana is even the best non-gunner gun, because as you have noticed it is good against all types of turrets, which are the enemy type that non-gunners most often want a gun to deal with.
Blaster is great for consistency, and the damage doesn’t fall off so hard solo. But then I pull out prisma driver and it’s very rewarding. Larger health pool in parties lets the crowd bounces and internal ricochets shine. Also more subjectively involving to use.
I definitely use arcana more than that thought I would though. Also giving pulsars a chance.
My main gripe with the blaster line is that it's just decent and doesn't have any real utility. The basic attacks just do damage and have a minor amount of flinching power, the charged attack is just a bigger version of the basic attack.
I would like to see the charged attack get a change to make the gun more useful overall. One thing that could be amazing is if the charged attack didn't get bigger. Instead upon hitting an enemy or hitting max range it would suck enemies in towards the middle and explode.
I figure the first hit would be about 35% weaker scaling up to 25% weaker based on 2* to 5*. The radius would scale up from about 2 enemies thick to 75% the size of a 3* Graviton Bomb. Suction would scale up. The damage of the explosion scaling around 35% to 45%.
It has to compete with driver/wands' high damage charge shots and mixmasters' higher DPS+status, but mixers aren't an option starting out and drivers require heavy stat investments to become good as well. It also combos well with swords.