I don't know about all of the options, but we just bought a "smart" tv (ultra-hd, although that may not make a difference in term of the smartness) and it has suddenly become very easy to watch my daughter's Netflix our Amazon prime; there are two buttons on the tv remote that make it really easy to switch to and from our cable box.
My husband just bought a universal remote that he is working on programming to make everything available on just one remote. Supposedly it works with about a thousand different combinations. When he gets home later I will ask him which remote it is (cost was about $60, I think) and how far he's gotten with it. I'm pretty sure that remote would work for including apple TV and Roku, just because they are such popular options these days.
I would love to get rid of our cable but I haven't found any way to get news channels without it. One of the few channels my dh likes to watch is Bloomberg.