They were quite durable 20 years ago too. It's just back then clock speed and performance was increasing very rapidly and it had a huge effect on the usability of your machine (especially if you were a gamer). You would likely upgrade and retire a working machine for the sake of a drastic performance boost every 3ish years.
Nowadays you could happily be using a 5+ year old i5 for full time development and moderate gaming with no issues at all. I'm personally at 5+ years now and I don't see myself upgrading for quite some time because everything I do still feels very snappy.
But compare that to something like a Pentium I at 75mhz (1994) vs a Pentium III at 1ghz (1999) and the performance difference was crazy. Over 10x the clock rate, but it's not just a "paper" boost. They are so different in performance that you can't even compare them. They are in leagues of their own.
(The buttons used to be plastic. Now they're wood.)
That's durable. It also does a much better job than any modern food processor, possibly because the motor is four times the size of what you'd get now.
There are 50-year-old cars still in service today. I wouldn't drive one, because I want to take advantage of the tech advancements of the past 50 years. But that doesn't mean cars aren't durable goods.
And even though computing is barely 50 years old, there are 50-year-old computers in service today. I wouldn't use one, because I want to take advantage of the tech advancements of the past 50 years. But that doesn't mean computers aren't durable goods.
This applies even if a 50-year-old car, which predates bluetooth, doesn't have built-in bluetooth. And it applies even if a 50-year-old computer, which predates HTTP, can't load websites.