It's barely overclocked, the change is lost in the screen refresh rate. Also the Game Boy Color was released 10 years into the GB's life cycle.
The DSi, however, was released 4 years into the DS's life cycle, doubled the clock speed, 4x the RAM, plus cameras and access to the digital store. The DSi was launched while the DS was solidly healthy and had a good install base, because of a power war with the PSP.
The 3DS was a "successor" 3 years later. It struggled because it was marketed as a successor, but didn't have great launch titles and lots of folks were happy with their DS. Their install base was so huge it was actually a problem. It was a 3 core device, two ARM 11 CPUs, and one ARM9 for DS compatibility, retained the DSi's cameras, and replaced the custom 3D accelerator inhouse developed by Nintend with a PICA200
The New 3DS, 3 years later, was a quad core device instead of dual core, ran at over 3x the orginal's clock speed, double the ram and auto stabilized the 3D feature. This was a significant bump in power, though the ARM11 arch was retained, and the GPU didn't run any faster.
The Switch would release 3 years later.
And of course, the DS itself was launched 3 years into the GBA's lifecycle, which was itself 3 years after the GBC. Every iteration retained backwards compatibility with the previous, but dropped compat for the one before it. Nintendo has launched a new, more powerful handheld, every 3-4 years for 20 years. Releasing revisions halfway through a consoles life cycle is the norm for their handhelds.
I think it's also pretty clear that they have bungled most of those. Nintendo needs regular revisions of their handhelds to cover the long gaps between their home consoles - that's why they didn't retire the GBA immediately when the DS released (calling it the "third pillar") so if the DS line tanked they could retreat to the GameBoy. And they did the same for Switch, if it bombed, ready to return to the 3DS. But now they don't have a separate handheld line from their TV line to sustain each other, and unlike MS and Sony they don't have a large independent empire with which to weather a bad year or two.
We can argue about what's a good idea for Nintendo, but regular refreshes is their trend, and they're under extra pressure in the Switch line because they no longer have two independent lines of hardware business. If the "New Switch" is a failure, they'll recoup to the Classic Switch, and retrench for the successor. If it succeeds, they'll phase over to the New Switch and run with that as long as the Switch "family" can go, just like they did with the DS.
famiboards.com
