[manmanic]

There are a variety of formal consensus algorithms uses for enterprise blockchains, but they are all some variant of voting schemes based on validator signatures. Nothing like proof-of-work is needed to ensure that one bad actor, or a small number of bad actors, cannot break the network's consensus. If you have just one validator, like QLDB, then you're back to a centralized scenario.

[wslh]

The problem is that having a non-BFT consensus is the same that using database nodes and if you use BFT consensus you don't have the performance required for most use cases. BFT-SMaRT supposely achieve 80k tps for a few nodes but when you scale to more nodes the performance degrades substantially.

Another issue against the DLT hype is that the blockchain does not provide security where 90% of the whole architecture is outside the blockchain, less if there are many few nodes.

[dlubarov]

There might be some constant factor penalty, but we can shard BFT systems much like we do with Paxos etc. See Shasper for example -- it won't have any practical limits on throughput.