You see this a lot. A new generation comes in to relearn all the old lessons. It’s also happening on the frontend “server side rendering is bad, it’s slow” to the latest frontend frameworks and thought leaders “you should be using SSR” (server side rendering)

ETL is hot again with machine learning. Companies have massive amounts of data they need to get in shape for models. The promise of a GUI anyone can use with little experience (low costs) means these tools are gaining traction again for the same lessons to be learnt from the last generation who moved on/out the industry.