As Torvalds pointed out in 2019, is that while some major hardware vendors do sell Linux PCs – Dell, for example, with Ubuntu – none of them make it easy. There are also great specialist Linux PC vendors, such as System76, Germany’s TUXEDO Computers, and the UK-based Star Labs, but they tend to market to people who are already into Linux, not disgruntled Windows users. No, one big reason why Linux hasn’t taken off is that there are no major PC OEMs strongly backing it. To Torvalds, Chromebooks “are the path toward the desktop.”
From my perspective, he is probably referring to chromeOS’s crosvm container, which virtualises a debian install (or other distros). Since Chromebooks are popular in schools, predominantly in the USA but even still globally, students are likely to attempt to gain further functionality out of their devices, and hence experiment with Linux, get used to it and possibly install it on different devices (or on that same Chromebook through the mrchromebox firmware) in the future.
Edit: alternatively, he could just be referring to flooding the market with cheap Linux laptops for specific purposes like education workflows or standard consumer workflows, just like how Chromebooks achieved that footing in the market.