Based on discoverability of zoom and the effort cost of adjusting the zoom of every site, I'd bet a lot of money on the vast majority of users in the world brow

Based on discoverability of zoom and the effort cost of adjusting the zoom of every site, I'd bet a lot of money on the vast majority of users in the world browse at 100% zoom over all others setting solely on the basis that it's the default setting (or 'laziest setting') and not easily discoverable.