My beef with Material Design is that it's too clever by half. It's often pretty, the animations are pleasant, but the interaction is just not intuitive enough for primetime.

To wit, I've encountered them for years and I still have no idea what a floating circle with a plus sign in it is supposed to represent. Almost every time I've clicked one, it's begun a process of flow that was not my intention, so I've learned to avoid them.

What Material Design is trying to do is to create a universal design language, based on the assumption that different apps designed in all sorts of different ways is a bad thing. While I admit that bad design comes in many shapes and forms, I actually feel like the context of an app should dictate how it is designed, and that in many cases it will call for something other than bold colored boxy components with assorted degrees of box-shadow.

I can think of lot's of situations where material design would be an improvement (any UK or US bank site really) but I can't think of a situation where it is King.

For example the text input box not having borders and all the slow animations. I struggle to think of a situation where Material is better than just basic css.

"Basic CSS" is very vague. When you use basic CSS you end up with ugly or inconsistent design. There's a reason we have CSS frameworks and design standards.