To play devil's advocate a bit: running software isn't free. If you're paying for an online service, the hosting cost to the company does scale per-seat. It's easy to say that the company only paid the cost of development once (and even then, more users = more development demand), but you're not a user of a single unit of developed software.
For streaming services, I think the development-hosting needle swings way towards hosting. Streaming video is the vast majority of their costs and efforts, so scaling prices per-user is the only sensible option. The "software" of those services is bad and interchangeable, and not what anyone wants or is paying for in the first place.
For streaming services, I think the development-hosting needle swings way towards hosting. Streaming video is the vast majority of their costs and efforts, so scaling prices per-user is the only sensible option. The "software" of those services is bad and interchangeable, and not what anyone wants or is paying for in the first place.