Trade Off for infinite ammo, all primaries were stronger in D1

I mean its because d1 was just simple. Your abilities and the perks on your guns were water balloons compared to this game so yeah the guns themselves were better. D2 is balanced around buildcrafting which makes sense because your primary and special weapons blow everything up and you have constant uptime on abilities that do some combination of nuke everything in sight, heal you on demand, or weaken your enemies in some way. Ill give you an example. My go to loadout is lightning surge warlock with heart of inmost light + synthoceps and I usually use it with tinasha's, lord of wolves and an LMG. Syntho lightning surge nukes everything in a 20m radius of you including champions, the void grenade weakens targets, phoenix dive heals you on demand, HOIL gives you constant uptime on all of these things, every kill with any ability gives you devour which full heals you, and song of flame gives you damage and a huge DR bailout. tinashas stuns every champion and slows/freezes groups of targets at a time and has no shortage of ammo, lord of wolves melts any boss or yellow bar even post nerf, and corrective measure with destabilizing rounds and killing tally just blows up any trash mob you look at with it in your hand. This is hardly even a "build" with uniquely good cohesion and synergy its just a bunch of strong guns and abilities smashed together. As good as it is its not even the full meta. This is what the game is balanced around. So yes your auto rifle at face value doesnt do as much damage. It can probably get some kind of perk combination that makes it good, like pyroelectric propellant with jolting feedback and eddy current, it's one of my favourites.

Get a Riposte.