> Are 1-900 numbers still a thing? Are all those people going to lose their jobs?

IIRC, the 900 “area code” is still reserved for that kind of calling in the North American Numbering Plan, but all of the US carriers have withdrawn from doing pass-on billing for 900 calls (in part, IIRC, because the government prohibited them from disconnecting service for nonpayment of those charges), so I don’t think they’ve been a significant business for a while, and most of that kind of business has moved to various online platforms.