Cloudflare is vague about this. Their terms of service state that an excessive amount of non-HTML traffic is disallowed (2.8), while they also published an article to their official blog in 2021 explaining how Cloudflare Tunnel could be used for streaming live camera footage.
I wish that Cloudflare could clarify this for once and for all. You’re not the only one who’s confused about this, there are many more posts regarding this both on this forum and on Cloudflare’s subreddit.