As to cellular—it’s a viable alternative for lots of people. Many people don’t need more than 10-20 hours of high quality video per month. 20% of people are already smartphone-only users, and that figure is growing. At the same time, those data caps are growing. Verizon’s 5G service has no data cap. Even if there is a soft cap of a few hundred GB, that’ll be a viable wired replacement for most people.
The trend in tech, by contrast, is the opposite. We’re not on the precipice of increased competition in search or mobile OSs. Indeed, with Microsoft throwing in the towel on Windows Mobile, there is less competition in that space than ever.
I don’t see how splitting up Apple or Google would increase the number of mobile OSs. There have been companies in the past that have tried building a mobile OS either for a specific phone or as an open source OS and none of them have really gained traction. There have been rumors for a couple years now of some of the phone manufacturers talking about building their own OS to use in place of android, yet those still haven’t appeared. Microsoft failed at mobile because they were too late to the party, people already knew which mobile experience they preferred.
That's not true, and I'm not sure where people get that idea. Slightly over half the country has two or more wired choices at 25 mbps, and that's as of a few years ago.
And if you're saying that texting my aunt in Bangladesh is a viable alternative to sharing pictures of my kids on Facebook, then it makes no sense to discount satellite, DSL, and cellular as viable alternatives to Comcast. (And indeed they are for many people--just over half the households in Comcast's footprint actually subscribe to its service.)
And phone service is not a viable alternative. Even 50gb (the standard cap it seems nowadays before throttling) gets you only 10-20 hours of video at high quality.