So this is not cel-shading. This looks like an actual cartoon. What technique are they using here?

Isn't it simply very well animated 2D drawings?

Yeah, good 2D animation with a chromatic aberration overlay effect and some film noise I'd say. Maybe a subtle blur filter as well.

That's beautiful!

Cel shading implies lighting. There is no lighting. It's all hand painted.

And it is all explained in more detail here.

This looks like an actual cartoon.

Sometimes things are exactly what they look like :)

Love that 30s style animation, specially those 1s cycles. No-one ever was standing still, gave a very fluid feel to it.

Pretty smart style too, lots of movement for a minimum of drawn frames.