And then you launch any of the included apps. Chrome wants you to sign in, calendar wants you to sign in, photos wants you to sign in, not to mention Google photos pushes notifications ads trying to sell photo albums.
The photo app will also try to sell you a premium subscription to store your photos online.
The phone is very much designed to be used with a Google account, you can avoid it, but the experience is limited.
Microsoft noticed that people liked having their photos automatically backed up and being able to share them with friends and family. Same goes for documents, being able to push a "share" button on a family finance planning Excel sheet is a lot easier than emailing it around.
There is a lot of crap in the start menu that needs to be removed, and the constant attempts to change the default browser to Edge needs to stop, but "please backup your documents so you don't get all angry at us when your HD dies" is not what I'd call an intrusive ad.
Yes, if you're going to use those apps, you may as well sign in with a Google account. I don't use them, though. There are plenty of better alternatives to all of them.
> The phone is very much designed to be used with a Google account, you can avoid it, but the experience is limited.
No, it's really not limited. It does take a little more setup to install the apps you want, though.
This is still very doable (or, it was when I got a new phone a couple of years ago). It wasn't even hard to avoid using a Google account.