My wife still uses our iPad 1 to watch Amazon Prime on, despite it being years since the last iOS update that would run on it. I'm quite happy with my Asus Transformer which is stuck on Android 4.2.
As the author of the comment you're replying to, I can agree with that. I also own 2 tablets, both of which are used by my 4-year old to play educational games. They are great for that. However, I'm limiting his time spent on these games and overall they are gathering dust.
This is because, while they seemed useful to me at first, they are big and bulky and not good for productive work and all the use-cases I had for them (i.e. reading websites and email, watching videos, playing some games from time to time) have been fulfilled by my smartphone. And here's the problem with a tablet - I always have my smartphone with me, whereas for a tablet I have to make the conscious decision of taking it with me wherever I go. And if I have to make such a decision, I would rather take my 13-inch MacBook.
Of course, one could talk about a convergence of smartphones and tablets. Heck, I just bought a Nexus 6 last week, which is a freakishly big 6-inch phone. And I love it, precisely because it lets me do things that are comfortable to do on a tablet.
But here's the problem that I'm seeing, from personal experience of course - screen size matters a lot when speaking about things you can do with a device and a 6-inch phone is already too big to fit in my jeans pockets. I'm not seeing phones getting any bigger than that, because of portability. I love my Nexus 6, but I'm already wondering about how I'll carry it with me in the summer. But 6 inches is also too small for many use-cases.
This translates in my mind in one thing - phablets like the Nexus 6 or the iPhone 6+ will take over the tablets market-share. But because of their size, PCs and laptops will still rule supreme, these classes of products (smartphones and laptops/PCs) being actually complementary.