I always see Rasberry Pi as more of an educational and/or hobby platform.  Kinda like if you're into trains, you might also be into model trains.  You can set up a bunch of Pis all in a cabinet, doing their thing.  Maybe as a cluster, so you can explore how to set up a cluster.  Maybe as a NAS, firewall, or router for the same reason.

And maybe you get good enough at doing this, largely because it's so similar to a full sized environment, you move on to larger deploys.

There are probably good business reasons to use a Rasberry Pi.  Perhaps they're good for lights-out management.

But I agree.  I don't see many of these situations being that much better with 8GB RAM.  About the only thing that would be useful for is perhaps GAN (general adversarial network) training, although I'm not sure if that benefits more from cheap RAM or GPU (which Pis don't have much to speak of).