In some update in the past the spine brake reaction animations were removed because they were too sensitive and triggered too easily, but it seems like the acceleration spine for swaying left/right and accelerating/deaccelerating were removed as well. I think both of these are part of the issue why people dislike the new driving that came with 1.7.

Overall you will read time and time again that the driving now feels stale, boring, bland, less reactive, stiff, and I think these subtle animations play a HUGE role in that. The reason is because they affect the player camera! Just like in real life the character should tumble back and forth and be thrown about when they accelerate, brake, turn or crash their vehicle. The animations add a lot more life and make it feel more dynamic.

In the following section I want to include some examples from the Discord, the first of which is:

Current 1.8 without these animations:

An older version that still has the animations:

I think it would remove a lot of unnecessary hate of the new driving - mainly when it comes to the aforementioned 'stiffness' that people describe here and there.