In the best case, web animations just cause bloat and burn through your battery. In the (common) worst case, they stutter or break or cause things to on the page to hang while they load.
Just don't do it. Your website doesn't need to look like a mobile app.
This is just patently false. Animations can give a sense of continuity and context for the effect of your actions. For example, let's say that you have an alphabetized list of people, and you want to add a person to the list by putting their name into an input box above the list. If when you submitted the name it just disappeared and appeared somewhere down the list, you would likely not know what happened. If, however, there was a transition where you saw the list adapting to the new data, you would be able to understand that you added an item to it.
Sure, there are good and bad instances of animation, but to state that at best it's a battery drain is just patently false.
In the best case, web animations just cause bloat and burn through your battery. In the (common) worst case, they stutter or break or cause things to on the page to hang while they load.
Just don't do it. Your website doesn't need to look like a mobile app.