The main goal is to improve their user’s browsing experience, by eliminating distractions and surprising media playbacks of unmuted content, and provide them with more control over the autoplay capabilities for individual websites.
Web browsers are moving towards stricter autoplay policies in order to improve the user experience, minimize incentives to install ad blockers, and reduce data consumption on expensive and/or constrained networks. These changes are intended to give greater control of playback to users and to benefit publishers with legitimate use cases.
Google Chrome’s new auto-play policy for Mobile and Desktop released in its stable version with Chrome 64 in January 2018. One of their main goals is to unify the autoplay behavior across platforms and to allow the user to control which websites and contents can be played automatically. Doing so, they won’t get surprised by an unexpected media playback or increased data and power usage by their device due to that. YouTube will continue to autoplay with sound, for example, if you’ve previously interacted and played a video at the site.
Safari 11 is using the so-called “automatic inference engine”, which decides, if media elements with sound are allowed to auto-play on the visited website by default, which won’t be the allowed for most websites, according to the Safari team. In addition to that, a new power-saving feature will prevent the playback of muted videos, if they are off-screen, or hidden in a background tab.
What about mobile devices
Many data providers charge based on the amount of data consumed, so the OS developers decided it was in the best interest of the user to not have a video automatically begin playing when the page loaded so it would not start racking up data charges. Instead, mobile web videos require the user to click them to start.