Not to say that they don't have valid complaints, but some of this is definitely selection bias. People don't complain about the things that have gotten better. For example, today, it's not rare for a car to last 10 years without serious issues. There are a bunch of car owners who have driven cars to 1 million+ miles and these aren't some specialty car, but rather the run-of-the-mill cars coming off of factory lines.

There's lots of good knives out there at price points that many people can afford. I personally own a Global 3 knife set (chef, paring, utility) that meets 99% of my cutting needs and cost $130. I've had them for 9 years and I expect them to last at least another 10 years. $130 is expensive, but not over a 20-30 year period. Same thing with my pots and pans (all-clad) which I expect to last me another 20-30 years, if not the rest of my life.

My iPhone is 3 years old. It has been dropped more times than I can count, but still looks new. The glass on it is simply better quality than what existed before. No, it won't last a lifetime, but it will last an acceptable amount of time for something that gets as much use as it does.

And with the internet, quality goods are more accessible than ever. With a few clicks, I have buy pens and paper from Japan, cooking-ware from France and Panama hats from Cuenca, even if I live in a small town in the middle of nowhere.

That said, my biggest complaint is with appliances. Good appliances exist (e.g. Miele, Speed Queen), but in general, there's little correlation between price and quality. You can buy an LG fridge for $1500 or for $4500, but they use the same crappy compressor, so the more expensive one won't last any longer (and in fact will probably break sooner because it has more features on it that can break).