Starbucks isn’t the standard for coffee. They’re almost more of a dairy and dessert company than a coffee company.
I'd think it is pretty standard for the type of person choosing to drink oat milk.
Oat milk is great for vegans or lactose-intolerant people and froths way better than the other non-dairy milks, so I'm not sure where the oat milk => Starbucks jab comes from. Either way, my local coffee shops started carrying oat milk much earlier than Starbucks.
Starbucks used to have a short, don't know if they still do.