So there’s an entire industry designed to get people to ‘trade-up’ to inferior, new equipment?

Yep.

Read the reviews. Every new piece of gear sounds significantly better than the one preceding it. How then is it possible for 40-year-old hi-fi gear to sound better than new gear? If each year brought significant improvements, older gear would have to sound awful compared with gear with 40 years of continuous improvement, but it doesn’t. Curious, no?