I also question the extent to which this is true.
Lately I've been helping my mom downsize. She's got boxes and boxes of household goods that she held on to because it belonged to her mother or grandmother or great aunt or whoever. Basically just, when the time came to clean out the old house, dump the kitchen cabinets into a box, put the box in the basement, and leave it there for 40 years.
And the thing that's struck me is how much of this stuff is cheaply made and barely holds together. Sure, there's the occasional well-built item that resembles the stuff I'm used to seeing in antique stores. But mostly I'm just getting a lesson in how much survivorship bias informs my perception of 20th century consumer products.
If anything the real trend is the shift to plastic, which can be more durable but is also more prone to complete instead of partial failure and generally isn't repairable. e.g. a tin measuring cup might dent easily, but can also be bent back into shape. A plastic one probably won't suffer anything more than a scratch when you drop it, but when it finally does crack that's the end of it.
Speaking of plastic, so many people nostalgically remember Tupperware as a quality product that's much nicer than what you can get nowadays. But the truth is it was a multi-level marketing scam and their products were often contaminated with heavy metals. It used to be a lot easier to prop up a brand image in the pre-Internet days, when consumers largely couldn't talk to each other en masse like we do nowadays.