At what point is it worth using a managed communication platform?

I'm building an app that needs 1:1 voice and video calling, and I keep going back and forth on how much I should build myself. I understand the basics of WebRTC, but once I started reading about signaling, TURN servers, scaling, monitoring, recording, and everything else, I realized the actual calling part is only a small piece of the problem. So now I need to know how people usually approach this in real projects. Do you build the communication layer yourself because it gives you more control, or do you use a managed platform and spend your time on the parts of the app that make it different? I'm not talking about huge products with millions of users just a normal application where reliability matters and you don't want to spend months maintaining infrastructure. If you've gone through this decision before, what made you choose one approach over the other? Looking back, was it the right decision?