These are the causes (among many others) that sunk Microsoft's Mixer and potentially Facebook Watch...
How? YouTube videos aren't all that prominent on Google and its search features are rather terrible.
What they do have is a semi working recommendations system. How hard would that be to replicate?
”$1 per 1,000 minutes viewed, $5 per 1,000 minutes of video storage”
Many years ago I remember that YouTube reported that 24h of video was uploaded every second. This means that your storage cost would increase by $432/s or $37M/d. This means that you are paying 14B/month by the end of the year just for storage.
Of course there are a number of factors that will work in your favour here: - You can attempt to focus on only hosting "popular" content instead of allowing anyone to upload. However this can make it difficult to draw new creators to the platform. - You can definitely negotiate a better rate.
However I'm still under the impression that if you want to create a YouTube competitor you are probably better of starting with lower level components so that you are in a position to reduce costs for old and low traffic videos. My impression of Cloudflare Stream is that it is aimed for people sharing a relatively small amount of content (probably just their own).