The big difference there is that Apple eliminated support for 32-bit CPUs and Intel GMA. Consequently, there is very little 64-bit software on Windows, but on Mac practically any application can take many GB of RAM.
Computers do go bad, though. I decided I'd ultimately retire that Pentium 4, because the cooler is becoming less effective. (Also, it can't play HD videos from YouTube and it consumes lots of watts for what it does and has always made a lot of noise.) The fan in my Toshiba laptop from 2005 broke and made lots of racket while overheating. The fan in my HP laptop from 2009 kept getting clogged and eventually stopped spinning. My PowerBook from 2005 just one day did not boot anymore.
I can use it to review my photos from the day and do some minor edits with gimp.
Bonus, it's about fast enough to run dosbox or scummvm and play standard def movies in vlc well enough. I can even emulate a Sega Genesis and hook up a controller and use it as a mini console.
It's been around the world with me many times, fits into the space a large paperback book would take. It's not "modern" by any stretch, is pretty beat up, but the large cheap storage device that happens to be a computer is very hard to come by these days. I've seen some newer devices with better specs, but they all insist on tiny SSDs, like 32GB drives, so they're an instant no-go.
I miss my netbook, which was terrible by current standards, I made it work as a dev machine for a couple months while in-between workstations at home. It wasn't ideal, but it also wasn't as bad as I would have thought. I'm sure it would still see use if my son hadn't somehow destroyed the screen.
[1]: To clarify, that's when I bought it. The model with Harpertown CPU's, etc. was available in Q4 2007.
Computers tend not to go bad. Instead, jumping on the feature bandwagon that drives the product line model to profitability makes us feel that 800 million cycles per second is useless. In the early aughts, out in my garage I had bootlegged Windows Advanced Server running on a 40mhz 486DX2 with 8 megs of RAM full time to serve up the occasional file off the 340meg disk.