An example of ill intent on Microsoft's part: https://mashable.com/article/windows-10-upgrade-snafu-analysis

If you haven't used windows in years then you might not know how bad it has gotten, but ... it's bad. Windows update is not just for security updates, it's also there to change users default browser to edge, their search engine to bing, trick them into using onedrive (too bad if the synced files get corrupted), old features get disabled for no good reason, it hijacks other browsers to show messages and change browser settings, ...

All those things are definitely not for security, but rather a way for Microsoft managers to meet KPI, for example: they want more users of a new application, so they remove the old way of doing things and boom, their quarterly report looks prettier. And to top it all off Microsoft doesn't test updates properly anymore in house, so it's the customers who are life testing that shit. And because those users have to keep updating windows for security, Microsoft has them over a barrel.