OP has this first:

> If a system has distributed-consensus mechanisms, many different forms of event-driven communication, CQRS, and other clever tricks, I wonder if there’s some fundamental bad decision that’s being compensated for (or if the system is just straightforwardly over-designed).

then later down in the article:

> Send as many read queries as you can to database replicas. A typical database setup will have one write node and a bunch of read-replicas. The more you can avoid reading from the write node, the better - that write node is already busy enough doing all the writes.

isn't this same as CQRS

Somewhat, though CQRS might advocate for separate read and write models. It might be something like the writer publishes an event that is consumed by something that updates the read model and queries go directly to the read model. Whether or not that is overengineering depends on the problem and load.

I thought cqrs was a code pattern where you segregate query models from command models, rather than something that specifies where the data is read from or is written to.