I say this as someone who has no experience whatsoever with ERP. But the entire concept seems like an anti-pattern. A kludge that's only necessary when your org lacks basic technical competence.
Why does everything need to be in a single monolithic system? Does HR really need to run on the same database and software as the manufacturing plant? Haven't we learned that small modular, independent systems with well-defined interfaces at the system boundary work. If for some reason manufacturing needs to talk to purchasing, why can't they just do so over JSON/HTTP endpoints or a Kafka message bus or even direct SQL connections? Trying to integrate by just locking everyone together into a single system that tries to be all things to all people sounds like a recipe for disaster.
But, again I don't really have any direct experience with ERP. So that's why I'm really curious what orgs that are actually technically competent do. If Google or Amazon or Netflix was using ERP, despite having the engineering firepower to build alternative systems, then I'd really think that there's something important to the concept that I'm missing.