As others have said, it's not so much that tinkering opportunities don't exist. It's more there's a slump in the market of doing relatively easy jobs for money. You can hack on esp32 all day, but there aren't many ways to make money doing so. Making software for the iPhone was (and is still, at this point) a pretty good gig.

I figure auto mechanics contended with this 25 years ago. Now it's hard to find someone to replace your water pump, if your vehicle even has one. Like auto mechanics, though, these machines still exist and there's still a big market for those skills. It might just require more legwork to find that work.

For the same reason computing used to be defined by a Commodore 64 more than by an IBM System/370-XA mainframe from the same year — they're the most commonly and most easily accessible computing devices.

Old farts like us think the desktop is the default kind of computer, but it isn't. Most computers are phones, followed by tablets and laptops with touchscreens, and desktops are the weirdest ones.