I actually haven't seen a study suggesting it did. My perception is that we have cheaper options now that used to be not available and as you said for those you get what you pay for. On top of that complexity of items increased drastically as people want more features which adds more points for failure.

But overall, at least based on my experience, a mid-tier priced appliance still goes a long way if you maintain it properly. The latter being a huge point. For example, for anything that use water the lifetime will heavily depend on your water supply. If you have hard water, the appliance's lifetime will be much shorter compared to someone who uses that appliance with soft water. That has always been the case though.