Most consumers are primarily on mobile devices.

Windows persists in the workplace where the cost to replace it is significantly higher than keeping it, and keeping it doesn't cost much to begin with. Part of that cost would be training, yes.

The other part is finding compliant equivalents for the rest of the software they use. If the MFA, VPN, chat, email, etc. are all already vetted and designed to be compatible, there's no way they'd want to switch. Many policies regarding proprietary information disclosure are also built off this ecosystem and the certifications Microsoft's cloud already has.