All of my research and effort has been hitting a wall so far in this regard: Is there any way to make video autoplay on Safari in iOS currently?
Some have mentioned video transcoding or using playsinline
(which works on Android), but nothing has worked for iOS / Safari.
EDIT: Updated title for 2024 since we've got a new answer that could be helpful.
Faced the same issue recently, ios happens to block the autoplay due to battery/power saving mode scenarios. Tried everything but the below combination seemed to be working fine for me. Apart from the muted & playsInline try adding type="" in your source.
<video loop autoPlay muted playsInline>
<source src="" type="video/mp4"/>
</video>