Indeed, Lisp has too many brackets!

However, how many different roles do they have apart from writing action perimeters?

The answer is 0!

And 0 times 10, or 100, or 1000 or well, just go for any number, it doesn't matter, that's still 0.

Also, note that Lisp has only parentheses. While in the end, it is a matter of taste, I don't think one can disagree on the fact Lisp only has parentheses and they serve only one purpose.

Other languages have in fact many roles for parentheses while also having brackets and many roles for them while also having curly braces and many roles for them.