The Division 2 vendors are glorified modification salesmen since no one really buys their weapons because they are useful. This might change in a promising future update when Cassie Mendoza gets Exotics and GS500 items in her stock.
Vendors in The Division 2 mostly serve as a way of rushing through World Tiers once players level up to 30 and then stop being useful except for the occasional high talent roll that would find a way into one of their items. Players would then buy the said item and recalibrate the stat into another piece of gear they found in the world.
This stands to change with the upcoming update to Cassie Mendoza, the secretive vendor who is supposed to offer the best items. Her stock will now include Gear Score (GS) 500 items as well as Exotic ones, probably on rotation from a limited pool like in the original The Division.
Speaking of Exotics, they will see a bit of an upgrade themselves. Players who obtained Exotic items and then upgraded their Gear Score would sometimes see worse stats for some reason. This will be fixed in the same update and stat variation between GS 500 Exotics will no longer be present. In other words, every GS 500 Nemesis will have identical stats and the same applies to all other Exotics.
Crafting bench is getting upgrades too. It will finally be able to produce GS 500 items and at this point, it's hard to gauge why it took Massive three months to actually do this since these items couldn't be used in recalibration which rendered crafting obsolete.
To top it off, the recalibration rule for crafted items will be completely removed. We may actually be able to hunt for perfect rolls now.
Title Update 5 is not just about improving the existing systems though since players will gain access to two new weapons - Carbine 7 and Stoner LMG, the latter of which is the signature weapon of Nomad from Ghost Recon Wildlands.
You can check out the State of the Game recap on Reddit for even more information.