Good point. If you never add anything that is not MS provided, Windows probably does a good job of keeping itself safe.
But, I don't know many people who never add any "Extra" applications to their Computer. All of those non-MS utilities, games, and applications provide holes in the fence that the malware can find and exploit.
After Microsoft abandoned Windows Explorer for the new Edge Browser, their security improved greatly.
On my Win10 system I have several browsers, and use them for different types of applications, and they all hold up to every attack I have exposed them to.
Our Win 11 pc has yet to report any attempts getting past MS security.
Most security breaches we have seen were due to somebody letting a bug in by ignoring a warning that MS security suite posted.
I still keep WebRoot installed and updated.