I expect that plateau will occur before it is only rural customers left. Why you ask.
1) Increasing fragmentation of the OTT market
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-- The user experience of the Hopper3 or Genie is light years better than the cloud "DVRs" offered by OTT
I can see these 2 things being a driver for some people to stay or come back to traditional TV distributors. Some aspects of cloud DVR are great: you don't have to worry about tuners, and your recordings are available on any device anywhere in the US with an Internet connection. The downside is that every service has different restrictions, and you usually have to chain together multiple services to cover all of the channels you might be interested in.
Sling - can't record any of the Disney networks (including ESPN), 50 hours max
Vue - Most locals have DVR restrictions, can't record premiums like HBO (Last week tonight problem), can't pause live TV for more than a minute or two, and recording expire after 28 days
Hulu - have to pay an extra $10 for the privilege of being able to forward past commercials, and even then it doesn't work if you pause LiveTV past a commercial break, it will still force you to watch the commercial breaks as you fast forward.
Youtube - CBS and CW shows are swapped with forced commercial VOD options overnight, record as much as you want for the other networks but recording expire after 9 months.
DirecTV NOW - all that time in beta for a 20 hour DVR that can be summed up in 2 words: train wreck.
FuboTV - Didn't even get series record until a few days ago, and it's still a beta feature. TIVO HAD THIS OVER 20 YEARS AGO.
Philo - Record all you want, but recording expire after 30 days.
Individually these restrictions aren't so bad, but depending on your watch habits this could leave you maintaining DVR inventory across multiple services, and having to track shows to make sure you can watch before the recordings expire or get overwritten.
Overall, I think YoutubeTV has the only DVR implementation that would give cable/sat DVR a run for its money. They do pre-fetch on trick-play so it feels local, with none of the lag that most services have. The obvious downside to YoutubeTV is that their channel selection is somewhat restrictive. They're clearly inking deals to get channels that people will tend to watch live (so mostly news and sports) so that they can turn that into a targeted advertising money maker.