> I wonder sometimes how much inflation this is masking
I've wondered this too. So many electronics or appliances from the 1970s are still working (I own some). Good luck finding that quality today. In effect, companies were smart enough to realize they don't have to bring costs down, they can just screw you on longevity and you'll have to come crawling back in a year or two. In effect, things are "cheaper" on the surface but more expensive over time. Not to mention the effect this has on landfills and pollution. It takes just as much gas to ship a 1970s stove as a 2020 one, but the 1970s one is still working and the 2020 one is replaced in three years.
IMO, this is driven by the middle class learning to optimize their spending. No more spending middle prices on mid-tier products when you can buy cheap garbage for things you don't care about in order to save up for the top shelf on the things you do. Suddenly, mid-price mid-quality items are unavailable at any price.
Absent is any ground between cheap garbage and expensive shit that actually works. Some products are in that middle-ground price range, but they're actually cheap garbage that's been marked up to rip you off.
This seems to have increased over time, especially as factories became better able to produce goods that use barely enough material to work at all, without a too-high defect rate. I wonder sometimes how much inflation this is masking—goods stay the same price or even get somewhat cheaper, but are significantly worse than before.