One member includes a list of favorite things, one of which is the Oxford Comma.
In my early years of education, teachers taught us to use a comma before and in a list of items. In later years, this seemed to drop out of favor. Could it have been the difference due to some teachers having moved west after college and other teachers having attended college on the west coast?
Technically either way is correct. However in many cases, lack of the comma before the 'and' can change the literal or legal meaning of a sentence.
It seems in at least one case the lack of an Oxford Comma cost a company Five Million Dollars > https://cavalletticommunications.com...-oxford-comma/
In another case it brought a lot of people to a lecture that didn't provide the content they thought it might.
jtk