My understanding is that the cutoff is determined by the component manufacturers refusing to provide firmware updates. Microsoft does not directly support all

My understanding is that the cutoff is determined by the component manufacturers refusing to provide firmware updates. Microsoft does not directly support all hardware configurations, and manufacturers have more incentive to support Windows/general purpose hardware long-term. ChromeOS has much lower market share so manufacturers have no incentive beyond what Google can incentivize monetarily (i.e., pay them to do it at a loss).