For a web developers is it good to learn Photoshop?

If you want to be a designer then yes, if backend then I'd say no

If you do front end work, then yes it’s a good skill to have, especially when designers are slow to do anything and you need a minor change, will reduce the frustration of waiting X days for something you can whip out in a matter of minutes.

If you work purely backend, then it’s still not a bad skill to have but you probably won’t use it.

I dunno

I do backend mostly but when the front end devs are busy I'll do some front end work but it's only basic photoshop skills you'll prob need

I just sketch things out on scrap prices of paper then scan them... I suck

Nothing's wrong with extra skills

Knowing photoshop is a very useful skill.
I am still studying but I have used photoshop for a lot of things.

Yes I use it all the time... but I'm a one-man band self employed full stack developer

If you want to design a website..yes
If you want to edit your photo to attract opposite sex..yes

It is always good to know new things, Photoshop is useful

If you are going front end, it would be really good to know about it