These are standards developed by the World Wide Web Consortium to lead the Web to its full potential. In particular, web standards will help to ensure that all future browsers will work consistently.
This will have the benefit of making it possible to escape from dependence on any company, or proprietary technology, as well as avoiding the time-wasting necessity of trying to create pages that look good on browsers that were deliberately designed to be incompatible.
Additional benefits of strict compliance with latest standards are simplified website maintenance, smaller files that download quicker, improved accessibility for people with disabilities and increased usability on devices other than current desktop computers.