I'm not sure if others are like me. Maybe they draw the line at two, or somewhere else. But a new HBO subscription service really just means that's one more service that I probably won't buy, unless I decide I want to give up what I already have. And maybe I will, because what I already have is likely to get worse. From now on, why would HBO ever license any of its shows to Netflix if it has a competing service? It is the same with CBS's forthcoming streaming service. I expect that means that anything CBS owns will disappear from the other services. As more and more actors get into the market, it means either I will have to pay more to see what I want to see or I will see less.
And actually, this is part of a larger problem. Recently we were in a period where I could easily find and watch anything I could think of. It started with the rise of home video stores in the 1980s and lasted through when Netflix DVD by mail service killed all the local video stores. Now that the model is changing to streaming, the selection has gotten more limited. For the first time in my adult life, it is actually harder to watch whatever I feel like watching, because the streaming services are all based on licensing deals and limited availability. That's assuming I am limited to legal video streaming rather than illegal downloads, of course.
I wonder if more streaming services, with more limited options within each service will push more people into illegally downloading video content.