How is animation created on the designer's side?

Question

Design

On the side of the layout designer, everything is clear - SVG, JS and CSS.
And how is the creation and design of animation (: hover, : active, interactive elements of the site) for the site from the side of the designer? The usual frame-by-frame animation in Photoshop (AfterEffects?), which are then sent as a separate folder to the layout designer in the archive with the main layout? How then to deal with page-by-page animation (smooth appearance / change of the element when scrolling)? Or sites without visible scrolling (for example, parallax)?

Answer 1

Now more and more tools are appearing, inside which the designer can create animation / behavior, while immediately generating code for the front-end developer.
Framer for example.
Or inVision Studio (currently in closed beta).

Answer 2

Why draw when it's easier for a layout designer to poke his face into another site and say "do it like here, only this, and this, and this"?

Answer 3

Most designers stupidly forget even to come up with havers, and not that the animations are full-fledged.
I used to either typeset or did in AE. That was enough. For AE, complex things like transitions between screens and the like are just right.