I think my argument is that we will find new things to store on our PC's similar to how we found new stuff to store on our PC's from the 90s till now.
I guess it is hard to imagine, but let's dream a bit...one ridiculous possibility that I've thought about is consider something like google glass. Imagine recording every moment of your day from your smart phone, and not just when you wake up. Why would you do this? Well, may be there for little things like having a meeting with someone and you want to remember details without writing it down. Why take the time to record it manually when you have the ability to do it in HD, for cheap?
Again, this is hard to imagine wanting to do especially for privacy reasons, but were things like facebook and twitter easy to imagine in the 80s? As things things have changed, so have social norms...I'm not saying this is a good or bad thing, I'm just stating an observation.
So, I happen to not have any HD vids on my laptop at the moment, but I have a normal video on my laptop that is 10 minutes long that is 70 MB. For something like recording video for 10 hours say, that's 6 * 70 * 10~4GB. So, yeah that's about 250 days (little less than a year) on your smart phone at 1 TB ignoring all other things (full seasons of vids of shows, as another commenter mentioned, stuff like raw gps data that could be added to the video, other things), so may be it isn't quite reaching the limit but it's a good example for how as we have more space for stuff, it is possible to imagine finding more things to fill your smartphone's new TB of storage with.