I mean the most glaring issue is zero dialogue choice compared to NV or most RPGs. Also, the story is too linear to be a true RPG too. Maybe you could argue action RPG, but in the classical sense or like the original games it comes nowhere close.
this video was 2 and a half hours so I don't expect you to watch it, but it does a great job breaking down how causualized they made Fallout 4. Doesn't mean it's a bad game, just a bad fallout game imo if that makes sense
Eh, RPG's if they want to tell a good story almost always have to sacrifice some choice for advancing a coherent narrative.
I guess it'd be awesome to have a fallout game where you could get up, get dressed, go hang around by the drugstore (get that reference!) but it's kinda' more interesting to get caught up instead with warring factions and the like that the... story... provides.
YRMV