At least when it comes to musical instruments, cheap instruments today are astronomically better than the cheap instruments I grew up with - and they are cheaper. The manufacturing process has become so good that what you get for $350 today, is about the same standard as what you'd pay $500-$800 for 30 years ago (which is probably closer to $1000-$1500 today).
As far as clothes go - I the cheap junk back in the day didn't last too long, either. Cheap supermarket jeans would last me maybe 1 season, before something ripped. Granted they probably only cost $20 back then - but the quality isn't too different from the H&M you purchase today for $50.
Counter-anecdote. I bought some Jeans from ASDA (owned by Walmart now, not sure about then) for 5GBP in 2005..
FIVE, POUNDS.
Crazy cheap by any measure; they were extremely thick, to the point where you could stand them up with no person inside them. They lasted me for over 10 years.
New jeans (at any price point) seem to wear out in the inner thigh inside of a year, and I am not as active as I was back then due to age. I also haven’t gained a significant amount of weight to account for this. I thought it could be caused by cycling, but I stopped cycling and the wear outs still happen. I thought it could be the quality of what I was buying so I bought more and more expensive jeans, alas, the same was true.
The best Jeans I ever owned are simultaneously the cheapest.
(side note; I also noticed that nearly all Jeans these days contain “elastane” which is basically plastic, which probably contributes to the degradation - Elastane didn’t exist for jeans in 2005, they were mostly still 100% cotton until the legging jeans fad and then it started making its way into normal jeans).
As far as clothes go - I the cheap junk back in the day didn't last too long, either. Cheap supermarket jeans would last me maybe 1 season, before something ripped. Granted they probably only cost $20 back then - but the quality isn't too different from the H&M you purchase today for $50.