We probably talk about existing telephony stuff too much here, but the reality is there are billions of phone about there that want to be connected to the web like nearly everything else. This is especially important for any business that wants to link its website with its internal phone system.
If you are a modern enterprise or contact center, odds are you connect your phone system to the PSTN using a SIP trunk. This approach is light years ahead of previous technologies, but what about allowing callers to come in from the web with WebRTC? Often this means buying your own gateway or connecting your website to a hosted API provider. Is there something like a WebRTC trunk?