You cannot zoom on mobile. That really is lame.

I’d suggest it’s a problem with your browser that it respects the zoom restrictions, regardless of the page’s choices. Browsers are meant to be user agents – agents for the user – not agents for the page.

Firefox > Settings > Accesibility > Zoom on all websites.

Many browsers have similar settings.

I'm on mobile (iOS Safari) and seem to be able to zoom fine.