“According to the HTTP Archive Web Alamac, 24% of desktop homepages and 29% of mobile homepages attempt to disable scaling by setting either maximum-scale to a value less than or equal to 1, or user-scalable set to 0 or none.”
One meta tag locks out every reader with low vision, and almost a third of mobile homepages ship it. ESPN, Discord and DHL are on the list. Safari ignores the tag. Chrome and Firefox on Android still obey it, so the people who need zoom most are the ones who lose it.