I think this is partly because the game actually starts out super linear? Like, technically you can go three different ways from good springs, but going one way leads to poison bugs of doom and another way goes to deathclaws of devastation...
So you're inevitably funneled through primm, then to the outpost, then to nipton, then to novac.
re: fallout new vegas
And like... Technically you can skip the big quests in all those locations, but it feels weird to me... Like, they're pretty major story beats imo, and they help you level up at an appropriate rate
Maybe I should skip them, though.....