I've had my Acer Iconia One 7 (model B1-730) tablet for three years now, and it's been my only mobile device for most of that time.
(I dropped my phone, an excellent LG G2, shortly after getting the tablet, which resulted in its screen breaking. I used it with a USB trackpad attached to it with popsicle sticks for a while, until I got around to replacing its screen. But the replacement screen was broken on arrival, worse than the one it replaced, and I never bothered to replace the screen again or get a new phone.)
Anyway, this tablet is awful. I can only say one good thing about it, which is that it's somewhat durable (though it does have a broken corner and a scratched screen, and some of the paint has worn off the back). Other than that: The vertical viewing angle range of the screen is from -5° to -15°. It has so little ram that it often can't keep two apps in memory simultaneously. (f I try to cross-reference between emails and maps or a website, I'll spend most of the my time waiting for each one to reload after viewing the other. Things in the background like Spotify playing music, Tinycore monitoring ram usage, and Twilight reddening the screen also get pushed out of memory frequently while I'm, say, browsing Reddit.) It has stereo speakers, but they're both at one end, so you don't get stereo when watching something in landscape. The Bluetooth hasn't worked in a couple of years or so. (It shows up as on, but cannot be turned off or used in any way.) The Wi-Fi hasn't remembered networks through restarts or Wi-Fi disabling/enabling in a couple of years. The Wi-Fi speed varies between less than 1 kB/s and several MB/s, from one restart to the next, with some kind of up/down trend over months. The battery gauge always read 95%, even when it was also saying it was done charging, for the entire first year I had it, which resulted in the battery getting damaged because neither I nor the tablet knew it was low until it was below what should have been 0% and the tablet just died. (I think I accidentally fixed that by unplugging and replugging the battery; the gauge has worked fine since.) Occasionally (sometimes when dropped, sometimes spontaneously) the screen would stop sensing touch, for which the only solution was a hard reboot (because I couldn't touch the onscreen button to shut down cleanly).
TL;DR: Don't pay any more than $10 for a B1-730. (Other tablets in the family might be better; I haven't tried them.)
So that's what was already happening, before the last couple of months. In the last couple of months, the battery finally wore out to the point that it lasted less than half an hour on a charge, so I started just carrying around my tablet with a USB battery permanently plugged in. Even with that, by a couple of weeks ago, it couldn't even last one minute on a charge. Soon after that, it was so bad that apps would crash when I'd try to scroll rapidly or perform other actions that involved strenuous animations, even when the tablet was plugged into external power (which I think was because it relies on the battery to handle transient loads even when plugged in).
Then, I tried restarting it because it stopped sensing touch at one point, and it never progressed beyond the boot animation. Forcibly turning it off and trying again resulted in a successful boot—that time. (This had happened once a few days before, so it didn't surprise me greatly.) But the Wi-Fi was slow after that boot, so I tried to reboot it again, and it got stuck again. It has not booted successfully since then, and not for lack of trying (and cache clearing).
I assumed that this was just the battery having gotten even worse, which leads us to the next log entry…