Evidence? 15 years? Security is a huge market. In every company, installing an AV is mandatory to for “compliance”. Every computer you buy with Windows, you get a “trial” AV license etc. And people, because they don’t think, will install it, then - because they think this is required, will try to get a cheaper alternative.
Whatever you do - Windows was born by putting a UI on a rotten core, developed for Stand-Alone boxes without internet access. The Internet access was “patched” into it. And because patching is so easy (we leave it to external entities), we also decided to patch in security.
Being in the security business for over 25 Years, I say: yes - AV is mandatory for the peace of mind as commercials teach you that you are not sucure otherwise.
If you really want to have a secure OS, all applications and libraries have to be developed with security in the design of the software. Taping a security patch on top of it will not do it. Adding AV will not do it.
But this is getting off topic. I’m gonna stop here.