I think even before dbt turned DE into "just write sql & yaml", there was an appreciable difference in DE vs SE. There was defo some DEs writing a lot of java/scala if they were in Spark heavy co's, but my experience is that DEs were doing a lot more platform engineering (similar to what you suggest), SQL and point-and-click (just because that was the nature of the tooling). I wasn't really seeing many DEs spending a lot of time in an IDE.

But I think whats interesting from the post is looking at SEs adopting data infra into their workflow, as opposed to DEs writing more software.