I especially noticed this in libraries/packages that were "community owned" in a company--instead of one team owning the package and being the authority on deciding the long term roadmap and communicating with other teams about feature requests, deprecations, documentation, bug fixes, etc, the community at large, where "community" was very broadly defined as a team that for whatever reason had an interest in using/maintaining/adding onto the package, would collectively own the package.
Naturally, the result was exactly the scenario you described. Each team hacked on their own bit of functionality for their specific purpose, while doing their best to not affect or break the increasingly precarious tightrope of backwards compatibility. There was no long term architectural vision, so there was a definite need for refactoring--and yet no team had the incentive to invest the amount of time needed to do that.The documentation was woefully incomplete as well, and few people understood how the entire thing worked since each team would only interact with their small fraction of the code.