The picture above shows that the desktop notifications button is displaying it’s enabled, otherwise it would say “Enable notifications” and not “Disable notifications”. However, there’s a “(currently enabled)” next to it, which feels unneeded since the button shows it’s enabled anyway.
Just a minor nitpick. 
Can’t we turn this into a checkbox, which has super clear non-duplicated semantics and fits in quite nicely?
Nope, because the button actually has four states. Permission needed, permission denied, permitted but off, permitted and on.
I added the “currently enabled” because the text on the button was confusing me as to what the current state is. If you have better text/icon combinations to use, please reply with them 
I agree with this, the presence of “disable” on the button means it is enabled. So I changed the "(currently enabled)" string to "".
