Some of those parens could’ve been replaced with commas and retain their meaning (that’s what I do to avoid nesting, so that it doesn’t get confusing).
I’ve never seen that being used, but it seems it’s a thing in English. What if you wanna best deeper? Do you go {}? Then <>? «»?
Not really an English thing so much as a math thing that makes too much sense to not use elsewhere. For instance, in math you might have x[3 - 7{3y + (a * b)}]. I haven’t actually seen them go deeper than three sets, though, so I’m not sure what would be next.