The iPad 3 was a very small CPU and GPU upgrade while completely doubling the screen resolution.
The doubled screen resolution caused the processor to be constantly taxed, so naturally it would struggle and heat up.
This was a device that was trying to be pushed as a gaming device, an every day web browsing and such device, and it would last for years. Applications were beginning to grow more and more demanding as time went on, and it just couldn’t keep up with the times.
The Apple Watch on other hand is basically the opposite story.
Ever since it went 64-bit with the series 4, it’s been barely challenged.
You’re not usually using anything CPU intensive, you usually don’t have tons of graphics flying across the screen, you’re not doing much heavy gaming or anything that’s really over-taxing the thing.
It spends the majority of the time on the watch face, and the rest of it having music played or measuring workouts.
At the point it’s at right now, caring about a new processor in your Apple Watch is like caring about a new processor in your iPod Nano.
No one cared about the specifications of those classic iPods because no matter what it could do what you wanted.
And I don’t see Apple dropping OS support for any of these watches for a really long time.