That is a good question and any answer I have will be subjective jimbean. I have an iPad Air 2 from 2014 going strong so that is 6 years old. This is the first real hardware failure I have ever had with any electric devices that I have basically been told to bin it, PC builds included for the last 20 years. So I guess I can’t complain. Spending £720 for 30 months is not what I call value for money. Five years would be nice as after that time hardware improves, older devices become slower and IOS support would probably end for older devices. Probably depends on if you need each new iteration of a device for your needs and you have that in mind year to year. When I buy electronics I expect/hope they last till I upgrade/replace them.
Same behaviour while plugged in KIA. It worked perfect for 30 months then within 2 weeks went from turning off 1 time a day to not turning on at all, mostly.
I did replace it with the new IPad Pro 2020, what a fool I am. Still prefer the older model with Touch ID and slimmer design.