I actually don't think it will.
So this is what the fragmentation actually looks like for now.
There is device fragmentation - Roku, Fire Sticks, Apple TVs, and then Smart TVs. Each one of these things plays various services.
And then there is service fragmentation - Netflix, Disney+/Hulu, Amazon, Apple, HBO+, YouTube and lots of niche services
What I think will happen is fragmentation will reduce on the device side and access will be more universal over time. Only difference will be which apps have prime time location on app and searchability. I think there is still value in developing great content aggregation and maybe service-agnostic recommendation engines.
As for the Apps, if they are all $10, people will pick 3 or 4 and be fine. Which will probably give them better control than they have had in the past over cable which gave them 3 channels they wanted and 200 they didn't want for the same price. For me, the big variable is football. They need to choose wisely and go on a widely available platform like Amazon or YouTube.