"So any media creation or gaming-focused PC priced about $2,500 and up should come with a 1TB SSD boot drive."
Why? Why should I put applications, games and data on my boot drive? I want all IO for the boot drive to be OS-only, as much as possible. Also, by keeping the boot drive smaller (250-500GB range for Windows), full-drive backups take up less space. HDDs make a ton of sense for some use cases, as there's little meaningful performance penalty for most games. Sure, a person can "Just buy it" and get a larger SSD boot drive, but the better way to make the assessment is data-driven.