Not everything needs to be D&D. Combat in Fallout is based more on positioning and how you use the items and help you have at your disposal (and a bit of luck) rather than simply having the best gear.
In theory, maybe, in practice... not so much. One of the bigger problems with modding the game is the impossibility to add more rewards/item into the game which wouldn't either be unneccessary or obsolete what's allready there. There's no cc in it apart from AoE damage or aimed shots (which are also nukes), and the positioning works in two ways - step aside while I AoE these guys, and duck behind a corner so you can take guys out with less resource investment. There are only 2 real buffs, one makes you immune to damage, one gives you 2 AP and makes you an addict, and the healing consists of opening your inventory to reload and also using as many stimpaks as you want.
When you look at it, shadowrun returns could've came out a year after Fallout 2 (with time-appropriate graphics), but it's own simplistic combat system seems like space-age tech compared to the fallout one. And that game give you a lot fewer inventory items, but quite a bit more to do with them. Just saying, I'm a huge Fo 1/2 fan, don't get me wrong, but having played and replayed them a dozen times, it made me really appreciate systems which do include options other than just shooting stuff.
I bolded the relevant part. This type of design only works because you're playing against other humans and because not only is every game short compared to an RPG but because every game starts from square one. This would not translate very well at all to a single-player RPG.
Well, you do have a point there, but if your ability slots were rotating so you could mix and match abilities you wouldn't need to start at square one all the time. And the human AI is kinda needed when it comes to Real time stuff and RTS stuff - with that out of the way, you probably could code an AI to handle combat encounters.
You make it sound easier than it actually is.
Allthough, yeah, I probably do. Still, if shadowrun had proper writing and a bunch of work done on it's party handling and combat options for the AI, it'd be quite good IMO. It's kinda almost there when it comes to what I'd call a satisfying RPG, or at least the bare bones of it.