Comment by WorldMaker

From my viewpoint, a lot of the submodule problems are effectively same as the monorepo problems, including how you end up with both problems. There certainly are factorings of projects into "microservices" and moving the dependency management problems out of source control to package managers of different types. Microservices and package management sure do have their own problems and trade-offs and there isn't a "universal solution", just what side of the trade-offs you prefer to be on.