It's relatively cheap in terms of raw hosting cost, but quite expensive in terms of maintenance / development effort, because p2p tends to be signficantly more

It's relatively cheap in terms of raw hosting cost, but quite expensive in terms of maintenance / development effort, because p2p tends to be signficantly more complex than server-based. This expense is upfront (unlike hosting cost which tends to only ramp up along with your platform's success), so it makes it a difficult space to enter. Jitsi for example is making a good effort, but the quality/performance/stability still leaves something to be desired largely because it leans heavily on browsers to implement some parts of the complexities, and browser implementations are inconsistent / have bugs that the Jitsi devs aren't able to easily fix across the board.