P2P doesn't require any computation on any server - it's essentially serverless. It doesn't make much sense to me at least to need to compress everything twice and have multiple buffers AND have to manage a server.
Well if any of the O(N^2) connections has unacceptable latency, you'd understand why a server is sensible. Reducing computation won't improve latency in the connections. One has no flexibility with clients but a server can be located wherever good connections are available.
There is flexibility - in the P2P model if one of the clients has bad latency - their buffer gets increased to prevent drop outs.
How is a server better in this scenario?