User blog comment:Wagnike2/Fallout 3 vs. Skyrim/@comment-1867168-20111124064828/@comment-4113369-20111124142545

They're not incomparable, or rather, anything beyond TES3 and F3 isn't incomparable, because they are really similar in technical terms, as well as in gameplay (except that Fallout uses a more generic leveling system). And you're not forced to level up your alchemy at all, it's completely voluntary. The idea of the leveling system is to get better at what you do simply by playing the game. If you have to force yourself to level up a skill, I'd say you're doing it wrong (then again, what do I know?)

And I think they're working (primarily, at least) on patches and DLC for Skyrim, not on Fallout 4.