Before you think about hosting, have you thought about transcoding? You can’t just upload a single format video and hope every browser will just play it, they won’t. You’d need to convert to several different formats for different browsers. That on it’s own is quite a challenge.
Regarding hosting, what you would need is a lot of bandwidth, as video is very bandwidth hungry, so I would go with a service that can easily scale that up for you, such as indeed AWS, or Google Cloud Platform or Microsoft Azure.
But seriously, tackle transcoding first. If you can’t get that right there is no point looking at hosting at all.