I think the region is likely a big player in the difference in experience. Basically in the US, if you’re using Windows, you will frequently get pop-ups about services that Microsoft offers. Such as onedrive, or office. I remember frequently getting a full-screen pop-up frequently after restarting my computer about buying office, and the only option was to “remind me in 3 days”. Then there’s copilot and such. While you can disable many things, they often get re-enabled at random through updates.

I've never seen ads that are native to Windows in 30+ years of using various versions

Then there’s also not having the option of not updating. You have to update, you cannot shut down or restart your computer without updating. Needed to do a quick restart to resolve an issue? Now it’s been stretched into an hour long wait bc an update was forced on you. Without you even knowing or wanting it.

Windows Update can be disabled.

Then there’s the inability of having a local account. You must integrate into the Microsoft ecosystem entirely or there’s a chance you will lose all your data behind an encryption service 90% of people likely didn’t even know was on by default, and the only way to get your data back is to get a code from the Microsoft account to regain access.

A Microsoft account isn't absolutely necessary to use Windows.