> Safari ignores directives by the website to disable zoom.
Yep, as of iOS 10 https://webkit.org/blog/7367/new-interaction-behaviors-in-io...
And thank god for that, there were so many sites that disabled zoom for seemingly no reason, and somehow it was always the ones with tiny text or images.
Lots of site owners disable zoom because they think they know best when it comes to content-size. Disabling zoom also makes the site slightly more responsive because when a touch occurs, the browser doesn't have to wait a few hundred milliseconds to see if a 2nd finger is going to be touched to start a zoom action.