Samsung M540 "Slyde" phone - The software was incredibly buggy including things like just randomly typing the wrong letter. Randomly bad tech is so much more irritating than tech you know is bad.
Google Nexus 7 (2012) - The tablet had defective chips that slowed down over time. Turned into a horrible slow piece of shit over time.
I still have the refreshed second gen version running, got an android 12 rom flashed and now it is being used with an amcrest camera as a privacy friendly nanny cam monitor!
Oh, remember the good old Nexus 7. Had only a fraction of its performance 1-2 years down the line...
Meanwhile, my Samsung Galaxy Tab A 10.1 2016 still soldiers on with good performance, even if it hasn't gotten updates in half a decade, and its internal 16GB space is beyond ridiculously small for today's standards and has to be cleaned up revery few months.