- That 7 or more nodes exhibit degraded performance, and that 5 is the sweet spot seems like a handy-wavy statement. I'd like to see numbers. And I believe those will be related more to implementation details rather than algorithmical limitations. Sure, with more nodes, communication overhead grows. But only a majority needs to agree, so there's no need to wait for the slowest node. Sure there's a sweet spot, but I wouldn't say it's exactly 5.
- Paxos does not perform leader election. There's indeed, no concept of a leader. There's only proposer, acceptor and learner. There's a leader concept in Multi-paxos, but that's a different story, and it's just a performance improvement, not a requirement.
- The original Paxos paper may be harder to understand, but "Paxos made Simple" is not. Probably easier to understand (IMVHO) than Raft's paper.
- The post assumes, as most Paxos implementations, that the three Paxos roles (proposer, acceptor and learner) are collapsed into a single node. They could be in different nodes. This may challenge some of the assumptions made about the "regular" Paxos algorithm.
- What the post proposes could probably be easily simulated with a varying number of proposers, acceptors and learners (like for instance having a lower number of acceptors than learners). This should result in the same benefits of the modified algorithm... but without modifying the algorithm. This is important, since original algorithm is proven mathematically.