The problem with tablets isn't actually a problem...
...because for the last 4 years they've all been more than good enough to do what we want from them. Hence no problem.
For me personally tablets replaced the need for me to carry a laptop around with me.
I still rock an iPad Mini 2. This still does everything I need it to such as being able to remote into servers, general office tasks, entertainment, reading etc. So far I havent really found anything that it can't do, apart from the stuff that I'm not going to do when mobile anyway.
My GF stll runs an iPad 2 - now 6 years old and it still does everything she needs it to, pretty much to the extent that she powers on her desktop about once a month.
To those who say that tablets were a fad: I disagree. The only reason that tablet sales have declined is that there has been no reason to update apart from a very few niche cases. Those tablets sold 4 or 5 years ago are still in use because they already do what people want of them.
And that kind of mirrors the entire computing industry over the last 5 years - It's got to the stage where, for most people, anything you bought within the last few years is already more than good enough.