If ure not doing coding or academic language (or a few other niche industry uses), don't bother, you shouldn't.
If you're doing academic or journalistic writing, there are so many required parenthesis all over the place, so they have a bunch of rules that you need to use brackets for certain things instead, depending on the system. If I remember my APA right, it's square brackets when citing within a sentence within parenthesis (like this [vicious_snek6, 2026]) or like this when introducing an abbreviation in a citation (Kotaku in action 2 [KIA2], 2026) or "when you have a quote and you wanna flex on their mispelling [sic]" which of course means their entire argument is wrong. And about 100 other stupid little rules that are far less useful.
It's still a mess and horrible to read, but the square brackets do help keep it cleaner, and signal that something other than usual parenthetical information is happening, there's a system.
If you are getting to the point where you think it might be useful because you have a lot of parenthesis already, just fix your writing, don't use square brackets.
If ure not doing coding or academic language (or a few other niche industry uses), don't bother, you shouldn't.
If you're doing academic or journalistic writing, there are so many required parenthesis all over the place, so they have a bunch of rules that you need to use brackets for certain things instead, depending on the system. If I remember my APA right, it's square brackets when citing within a sentence within parenthesis (like this [vicious_snek6, 2026]) or like this when introducing an abbreviation in a citation (Kotaku in action 2 [KIA2], 2026) or "when you have a quote and you wanna flex on their mispelling [sic]" which of course means their entire argument is wrong. And about 100 other stupid little rules that are far less useful.
It's still a mess and horrible to read, but the square brackets do help keep it cleaner, and signal that something other than usual parenthetical information is happening, there's a system.
If you are getting to the point where you think it might be useful because you have a lot of parenthesis already, just fix your writing, don't use square brackets.
You forgot to mention that the rules most likely change between languages too.