It is obviously both.

But you cannot have earbuds without microchips. Those things are often smaller than a single vacuum based transistor. Same with cell phones. Brick Phones weren't giant (just) because people wanted things to be bigger. They were giant and worthless for anyone other than Zach Morris because technology did not allow otherwise. And that is why basically every year (up until maybe a decade ago?) it was "And this is smaller and lighter because who wants a giant ass phone".

But... there are trade offs to that. When all the meaningful logic in a device is on a single board/chip, it can be REALLY small and you get a lot of inherent shock protection (nothing to get dislodged when it hits the concrete). But that also means that diagnoses increasingly involve x-ray machines and repairs are largely "replace the chip".

And, like I said, that is why the fairbuds are still full of glue for the actual internals and they don't sell the actual chips. ifixit commented on this on how it is likely for waterproofing reasons but... that still means you can't actually "repair" anything but surface damage and swapping out a battery (And while I am not convinced that is a meaningful value add, I still like it). That is the fundamental limit to when you aren't even dealing with chips with the spider leg prongs and are instead dealing with significant amounts of logic in the substrate of the board itself.

So if you want something that "values repairability"? You aren't getting earbuds. You probably aren't even getting headphones that (sane) people can just pop in their bag and go. You are looking at the bigass cans targeted at people who have Thoughts on psychoacoustics. Or, to put it in computing terms, you aren't buying a cellphone. You are buying a desktop. (... also, good luck fixing your motherboard. Because even if you identify the short and bypass it... do you really want to put an 800 dollar GPU in there?).

Which gets back to understanding what does and does not make sense to focus on "repairability".