Yes, you could. The last time someone I know spoke to them, the standard enterprise plans started at $5000/mo and got you some very nice freebies. Cloudflare's also announced managed WebRTC APIs (in closed beta) which look promising for creating meeting rooms ala Zoom.us. I imagine, these are already available to tech-shops on enterprise plans.

Though, mux.com is decent too, from what I've heard; for certain workloads, LiveStream and Vimeo might be cheaper.

There's Peer5, PeerTube, and BitTorrent in the P2P space (among many such solutions).