> But engineering hours saved is pretty much a wash compared to DIY once you hit that first edge case that the tool does not handle elegantly

This is probably the exact crux of the argument, and I wonder if it reduces the overall demand relative to the growth in the industry. Do you need 10 engineers (like a decade ago) when 1 (great engineer) can deal with the bulk of the work with "better tools" and then DIY on the edge cases. This has been my experience with the modern ETL tools.