Microsoft and the Surface line is not a great comparison imo, since their hardware specs aren’t exactly unique, and every feature Windows has on Surface is the exact same on other brand laptops; while Pixel devices have Android features exclusive to them and not on any other Android phones.
If Google wants to sell Android/Google services and not just Pixel, wouldn’t it be better to trickle down more features to mainline Android? Currently, the only previously Pixel-exclusive feature that is now available on any Google One subscription (that I know of) is Magic Eraser. Plus, Google now developing their own SoC and promising 7 years of software support for their hardware, means that they probably do care about hardware. (And we all know where Google products end up if they don’t care enough about it)
Though admittedly I’m not a business analyzer, and I still need to sit on this question a bit to conclude my thoughts (problems include how Google would be able to put Pixel features into the hands of other phone manufacturers to improve Android). Appreciate the answer anyways.