Opinionated thing. Devs, Bethesda and Obsidian, all want the better items out of reach until investment time is put in.
But how Obsidian approached it unlike Bethesda(Though their approaches were similar) was that every type of weapon should have tiers and all varients easily obtainable for all Skills from the start. And New Vegas due to its area has firearms almost in every corner.
Normally I'd automatically say weapons should be harder to obtain. But that'd be artificially constricting the player, like not getting PA from dead BoS in FO1. And it's not an easy solution.
Any game start in lower tech faction areas with surrounding areas not having a ton of weapons would be a way to smartly cut off a flow of firearms til later. I.e. Tribals and immediate region being tribal lands and mostly factories and homes or something else.
But that's just randomly off the top of the head.