Motion with a purpose
Example article. Sample writing for this page.
When a panel opens from the button that triggered it, the movement helps explain the connection. When every element moves at once, that connection becomes harder to see.
A useful way to check an animation is to remove it for a moment. Does the change become harder to follow? If the answer is yes, the movement is probably doing something useful. If nothing changes except the amount of activity on screen, it may be worth leaving it out.
Timing matters too. A short transition can make an interface feel responsive, while a long one can make the same action feel like a wait. Choose the moment that needs attention. Keep the rest of the page still, and make sure it works just as well with motion turned off.