How does punctuation evolve?

A lot of punctuation was developed by printers. It was developed to give those who read out loud an indication of when to stop and pause.

Grammar rules develop as academics felt the need to standardize and proscribe how to spell and write. That’s what motivated Samuel Johnson, and Noah Webster. (Webster was also trying to differentiate American English from Britannic English). And others worked on grammar to reduce confusion and ambiguity.

English punctuation was originally developed for rhetorical effect – it told the reader when to pause when reading aloud. But nowadays there’s a trend to use it for grammatical purposes.

English grammar is not developed by academics. Rulebooks don’t decide what English grammar is, populations do. Before English was studied or taught, writers like say Shakespeare were able to write clearly and unambiguously. The point of prescriptive grammar books isn’t to reduce confusion or ambiguity, it’s to tell people how they are supposed to talk if they want to be accepted by the in crowd.