“Higher quality” isn’t an objective measurement though. And it certainly doesn’t matter if the end result is that people cannot afford to buy it.

What I’d be interested to understand is whether changes to materials (be that buildings or home appliances) has caused an increase in the cost to manufacturer.

I’d wager most things have gotten cheaper to produce these days because the same improvements in technology that can be integrated into the product also applies to technology used to reduce the cost to manufacturer. Plus if wages are below inflation then any labour costs would have declined (relatively speaking) in that time too.