Functional is all about reification. You take a set of things in, you apply/map/collect/fold/whatever, you eject a set of things out. That is 100% functional--every time you supply the same inputs you get exactly the same outputs. The point of functional programming is that you avoid mutation and hidden state.

And, um, side note: dataflow programming is almost always considered functional programming.

Object oriented, by contrast, is all about hidden state and mutation. I send a message or call a function on that object over there and fingers wiggle and magic happens. But I don't know what or when or even if it actually happened.

And increasing evidence suggests that MVC doesn't work beautifully today because it doesn't parallelize, and it scatters state between uncooperative things. Just ask every single GUI that exists--every single one hangs because somebody made an oops and put too much work on the single, blessed primary thread. Or they have janky scroll. Or resizes leave gunk on the screen. Or your system flashes and jiggles because it's too busy reflowing everything in the universe. Or ...