I get what you're saying, but you need to consider two other things as well. First of all, there are very few examples where you don't want competition. The fewer services, the less pressure on them to provide an actual good service with good prices. I can see those services that don't manage to do that in the coming years fade away, while at least Netflix, Disney, Amazon and HBO survive.
Second, and this is building on point number one, there's not like there's a set amount of content that's now being shared by more services than before. If that was the case, there would be less content on Netflix now than 2-3 years ago. Instead there's much more, because of original content.
More services may lead to there being more content than before that you don't have access to, but that's because the "content pool" grows. If you just keep one service, like Netflix, you'll still get more and better content than before the competition entered the market.
