[ihuk]

Can someone explain why that button/menu even exists?

It shows all the extensions and you can quickly pin/unpin them but is that something people normally do? I believe most people decide if they want to have extension in the toolbar or not when they install it. All other options are in a submenu so it takes two clicks to get to them at which point you might as well open `chrome://extensions/`. And then, to add insult to injury, you can't disable extensions through extensions menu. You have to go to `chrome://extensions/` for that. So what's the purpose? Pin/unpin? That can't be it.