I think SQL alone is great if you didn't drink the microservice kool-aid. You can model dependencies between pieces of data, and the engine will enforce them (and the resulting correct code will probably be faster than what you could do otherwise).

Then you can run A,B,C and D from a consistent snapshot of data and get correct results.

The only thing microservices allow you to do if scale stateless compute, which is (architecturally) trivial to scale without microservices.

I do not believe there has been any serious server app that has had a better solution to data consistency than SQL.

All these 'webscale' solutions I've seen basically throw out all the consistency guarantees of SQL for speed. But once you need to make sure that different pieces of data are actually consistent, then you're basicallly forced to reimplement transactions, joins, locks etc.