[trashtester]

That's a good analogy. SQL RDBMS's, just like Java and other languages with GC have huge utility in a multitude of enterprise software situations. These probably make up the majority of software systems and lines of code out there.

Then there are a few domains that NEED other solutions. In terms of CPU cycles these may be consuming more resources. These are operating systems, game engines, ML libraries, search engines, social media platforms and huge webshops like Amazon.

But to store all data in Spark or MongoDB just because that's what <insert Cargo Cult idol> is doing makes about as much sense at programming everything in C/C++.