You have it backwards. It actually used to be the standard.
“Until the 18th century, the apostrophe was extensively used to indicate plural forms. Its use for indicating plural “possessive” forms was not standard before the middle of the 19th century.”
You may want to re-read that section as it’s not saying what you think it is; the whole section is how the apostrophe was used for plural and singular possessive forms changed (and there’s a “citation needed” for your quote too).
“An apostrophe followed by “s” was often used to mark a plural;[4] specifically, the Oxford Companion to the English Language notes that
There was formerly a respectable tradition (17th to 19th centuries) of using the apostrophe for noun plurals, especially in loanwords ending in a vowel (as in … Comma’s are used, Philip Luckcombe, 1771) and in the consonants s, z, ch, sh, (as in waltz’s and cotillions, Washington Irving, 1804)…”
That’s a way better quote! I’m still not sure that saying “it used to be the standard” is quite right, but it was definitely common place in specific circumstances and our avoidance of using it for plurals is a more modern invention.
I personally prefer the modern usage as it’s less ambiguous, although there’s some bias there I’m sure.