I think it makes more sense to have someone specializing in OPs and someone specializing in feature delivery. They are totally different skillsets. If you have both great but just demanding regular feature devs to also figure out all the network plumbing and deployments is just regular old business folks squeezing blood out of rocks.
It's not about forcing every Dev to learn every aspect of Ops work. It's about ensuring the team that builds the feature manages its delivery end-to-end, including dev, test, deployment, failure response.
The reason for this is, as I pointed out, because the organisations that created a hard split had much worse outcomes for customers and themselves. This split might have been necessary in the past, due to the vast gap in skill-sets and operating environments.
However, most orgs now will create a different split where a team manages the underlying infrastructure and tooling (to varying levels, depending on the specialisation required), but developers are responsible for ensuring their code Runs on Prod (tm). This does not mean developers are regularly fitting their own server racks and hand-wiring their networking infrastructure. It means, for the third time, developers own the delivery of their code to prod, end-to-end.
I believe we now have enough info to quantify the tradeoffs.
Dev is the sperm, Ops is the egg (or vice versa).
And it takes time for the sperm to talk to the egg. The sperm must travel. He types in Slack "Hello <Name>, I have simple trick to save money for bewba service.". The egg must travel, type in Slack, "I can't find bewba service in our catalog but I can't say that out loud".
Through time and effort, the sperm and egg finally connect, and the bewba service's money guzzling is shaved.
When the scenario is right, the travel time is not worth it. We kill of one of the sperm and egg, and accept the risks. The killed sperm-or-egg leaves the circle, and everybody in the circle is satisfied.
