That completely depends on what you are comparing it with.IMO this isn't true. Pyra's CPU falls well short of modern standards.
Are you comparing with desktops or full-size laptops? Sure, then the Pyra CPU is not very powerful. Not particularly weak either, just rather "meh" and the kind of thing you would expect to find in low-end machines. But that's not a fair comparison: desktops and laptops have a power budget and physical space budget that is an order of magnitude larger than what we're talking about here.
Are you comparing with chromebooks, tablets or phones? Then it's pretty much state-of-the-art. Not the best there is (the best cannot be obtained by anyone but the giants like Samsung, Apple, etc), but certainly still high-end.
Are you comparing with handheld game consoles? Then it's very powerful. Compare:
- New Nintendo 3DS (released in 2015) : 268 MHz ARM11 MPCore quad-core, 256 MB RAM
- PlayStation Vita (released in 2012) : Quad-core ARM Cortex-A9 MPCore, 512 MB RAM
- GCW Zero (released in 2013) : Ingenic JZ4770(MIPS) @ 1 GHz, 512 MB RAM
- Nvidia Shield (released in 2013) : Tegra 4 (1.9 GHz GHz quad-core ARM Cortex-A15), 2 GB RAM