Any type of tablet is not fitting into almost anyone’s pants, while a Note or other 6"ish phone can fit many people’s pants.
Bags maybe even more liberating in terms of size, sure, but a 6" can still be one-handed for calls or basic texting while anything 7" or more is starting to leave that realm for anyone who isn’t Andre the Giant or his Posse.
Of course if someone finds that a 7" or 10" tablet is the best device for their go-to mobile device for daily use, I mean sure. Maybe a little drop holster or just a purse-type carry bag, or a fanny pack that can handle an iPad mini. But it requires in all cases special consideration for transport. A 6" device for many people will fit just fine, if a little snugly, in the common smart phone transportation schemes society has figured out so far.