If I’m paying roku/Apple for a box and then I buy channels who get a cut of my subscription money from Roku/Apple who combine the channels into a guide, it’s sounds a lot like roku/Apple is my new cable provider
You're not wrong, although there is a lot of free content on Roku, and the devices work for screencasting, networked media playback and probably some other features I'm not aware of. The main reason people are doing this right now is because there are more provider choices and a lot of them are cheaper, even if you're using more than one. It's more modular than what the "real" cable companies are offering (not to mention no more equipment rental fees), but at the end of the day the pendulum will probably swing back toward consolidation and people will once again be left with relatively few/expensive options.
Major networks over antenna is more than 50% of my usage even with the current boon of a cheap "cable" plan through Roku. Individual networks also have a reasonable incentive to continue offering a la carte options. I'm paying $20/mo for ~60 cable channels but the truth is I really only watch 3 of them with any regularity. Even if BIGCORP sucks up all the other channels and demands $50/mo for them I'd probably still be happy to pay $20/mo between those 3 channels I watch.
We'll see how things shake out. I'd probably use Roku purely for performance and aesthetics at this point. Somehow an HDMI stick the size of a pack of gum runs circles around a FiOS cable box the size of a Sherman
