Separate streaming networks are not "à la carte". There's a big difference between one service giving you different prices depending on what you want to watch and several dozen services charging you a flat rate for all their content. Different services have varying levels of quality and stability, and have different user interfaces that may or may not support the same features. (For example: on my dad's Android-based smart TV, you can use a Bluetooth mini-keyboard to type in a search in Netflix, but not in Amazon Prime.) Having a small handful of mature and highly functional streaming services isn't ideal for competition, but it's way better for most consumers.
Agreed, I don't really consider streaming services "ala carte." But I do think the benefits of a subscribing to 4-5 streaming services over subscribing to a big cable package too big to ignore.
If you're not a cord cutter, or it's not for you, that's fine. But streaming services are the future, while cable and broadcast are the past.
I have no doubt cable TV will go the way of the dinosaur, or at the very least, will begin to change drastically over the next 2-3 decades thanks to the proliferation of more streaming services.
Live in the past if you want, i'll be with Star Trek in the future.