Why do birds like bird baths?

A bird bath is a small purchase but it brings years of happiness. Birds love to sit in water, flutter their wings in water, and they'll line up and wait their turn to use a bird bath. The main thing for people to do is to change the water, keep the water fresh and clean in your bird bath and you'll have happy birds visiting your bird bath. But why do birds like to take a bath? I've tried to find out and, from what I've read, science hasn't really answered this question. There is one simple answer, it is that they are having fun, like people they like to cool down on a hot summer day, they like to be in water, it's just a fun thing to do. That's what I think but, of course, I could be wrong.

Here is a robin in our bird bath, May 1st, 2022.