Here's a standard-structure, VC-funded, exit-oriented startup to consider: make video calls reliable. As in, you provide a guarantee and pay the customer if the call didn't work.

Wired headphones could be one part of the solution. They're just far more reliable (if they don't break, which they will). But if the reliability of video calls can be improved so that it's literally as reliable as talking to someone next to you in a quiet room, I bet lots of people would pay for it. There is so much latent frustration about unreliable calls, even with the best setup, even in NASA, in DoD, corporations, zoom and other platforms fail to perform reliably in so many cases.