That's not accurate, my device a Lenovo Chromebook S345 supports linux containers & android apps and is absolutely not a flagship. You'd struggle to run windows on a similarly priced laptop (cost me £150 a year ago).
On the SSD size, it's often the RAM that's really limiting for the linux subsystem. It's the same issue as on cheap windows laptops, only a tad better as ChromeOS is more frugal and orchestrates resources more aggressively.
And even in those, the lilliput SSD sizes make them hardly workable versus w regular laptop for the same price range.