The implication wasn't to use the raspberry pi toolchain. Just that toolchains are required and are a critical part of developing for new hardware. The Intel/AMD toolchain they will be competing with is even more mature than rpi. And toolchain availability and ease of use makes a huge difference whether you are developing for supercomputers or embedded systems. From the article:

"It uses technology called RISC-V, an open computing standard that competes with Arm Ltd and is increasingly being used by chip giants such as Nvidia and Broadcom."

So the fact that rpi tooling is better than the imitators and it has maintained a significant market share lead is relevant. Market share isn't just about performance and price. It's also about ease of use and network effects that come with popularity.