What we have here is the economy of scale working against the consumer.
Comcast has spent the last few years acquiring new customers the Wall Street way, by buying them. Now that the well of prospective buyout targets is running dry the emphasis is to maximize customer loyalty. The easy way to do that is to get them by the proverbial gonads. A customer that has all of their data services under contract and with one single provider is less likely to migrate due to any one service deficiency.
Comcast's new focus is to get as many if not all of their subscribers signed up for Internet, T.V. and Voice service. They may not have a problem now but unless they make the hard choice and start beefing up infrastructure (never a profitable short term solution) they are going to run out of capacity somewhere along the line.
AT&T is another that comes to mind, maybe even Cox but I haven't used them for decades.
The thing is, they have a backbone that was designed for delivering a fairly modest bandwidth, like DSL and the market requires much, much more.
At least they're not in the cellular business.