The speakers were nice when new, but after 20 or so years, the rubber around the cones began to deteriorate and the cloth covers frayed and developed runs. Even these M-Audio studio monitors I picked up in around 2005 are starting to have issues with the plug jacks.
I imagine it's worth with headphones ear cushions are usually made from synthetic materials that tend not to wear well. Plus they get moved around a lot and are at risk of getting dropped or crushed. I can't say that I've owned a pair of headphones that received frequent use for more than 15 years.
Replacing ear cushions is even easier than that: you order replacements, pull off the old ones and tug the new ones into position. It takes slightly longer than changing the batteries in a remote control, but much less time.
I have a 60W stereo amplifier from the 1970s that works and sounds great. I have an FM tuner from the 1960s of excellent quality.
I no longer have cassette tape decks, but I have a reel-to-reel machine from 1962.
There are speakers from the 1960s and 70s that are worth owning and using; there are lots from the 80s and 90s that are not.
There is so much to expand on there, too. Commoditization, while democratizing in some senses, loses the plot often.
(Say, a Fiio X3duoo player ($75), a 128GB microSD card ($25), and one of N different Chinese IEMs depending on preference, all under $100 and most under $50. TRN V90 is about $40 and does a respectable job.)
It's worth getting old headphones if they were the real top of the line like Stax electrostatics, since you can't afford new ones, but those were especially poorly built back in the day.
As for open headphones like AKG, people praise them for critical listening but I've found they're not good in realistic situations where there's any background noise at all. I can't get a separate soundproofed listening room in my apartment, so if the fridge decides to turn on, I can't hear the bass in an open headphone anymore.
There are SM58/57 mics being handed down to grandchildren.
My parents old Marantz receiver goes for $800 on eBay these days. I think we pitched it somewhere around 1994 for a setup from one of those Best Buy Sunday flyers.
But I've had my AKG K240's for years and they're tireless. Not suitable so much for running around town, but they've been made since the 70's nearly to the same spec. The cable is removable, so are the ear pads and both replaceable.
And they aren't even expensive, relatively speaking. Great for mixing and general listening. Can't say enough good about them, really. https://www.akg.com/Headphones/Professional%20Headphones/K24...
edit: My opinions are so very different from an article another user posted about the same (which strangely runs counter to the larger, repeated experience and sentiment). They've always been lauded for their very open, lively soundstage and even, clear response.