If you want to drink your own wine in a restaurant, you have to pay for that, too.

This isn’t much different; there still are plenty of non-Google options for creating presentations to choose from that do allow using your own font.

If SaaS is a restaurant, what's software I purchase? A personal robot chef with an infinite ingredient supply, no charge for using my own wine?

I think that supports the "Where did things go this wrong?" sentiment.