In that case your system is a legitimate candidate for Micro Services.

Services that can each be maintained by a small team, with a clean, understandable API, appropriate protections for data (both security and consistency) and easily predictable cost and behavior.

Then you can compose these services to get more complex functionality.

Yea I know microservices, depending on how you do it this comes with a ton of extra complexity. There are microservice architectures out there where each microservice seems to have a different tech stack, so now you have to hire all kinds of talent. Can work out well too, I believe just doing it in Elixir would save one a lot of headaches

In general it doesn't happen unless the business itself is swept away by leaner competitors.

Whenever I asked customers what they wanted from their new systems they always started by saying we want to match the existing system.