You're describing an Enterprise Service Bus, a concept that has been around and implemented for decades:

https://en.wikipedia.org/wiki/Enterprise_service_bus

Spoiler alert: it's not the beautiful, decoupled silver bullet it seems like. The concept makes a ton of sense, but good execution of it is difficult. The biggest issue I've run into using systems that use this pattern is throughput and latency. Most shops design and deploy their systems in such a way that as soon as there's a little bit of traffic beyond the norm, the whole thing gets clogged and backed up for hours.