Chrome has it, but it's hidden in menus. Android has it as an OS feature with a really unintuitive interface. It also fails the first time you try to read any page, but works the second time... It's clearly not something they want you to use.

True. Firefox's reader view is a one-click button in the address bar, whereas Chrome's is buried in the application menu > More tools > Reading mode. And even then, Chrome only shows the reader view in a narrow sidebar, leaving the messy page open.

This is indeed my favorite FireFox feature. Sometimes it even helps get past article paywalls to read the article.