To illustrate this, look at OsmAnd's most recent blog post [1]. They've recently been looking at adding pretty extensive Astronomy features. Before that, they added a lot of nautical tooling [2]. This is all very cool if you use that, but if you don't, the laundry list of such features make it harder to find the features you do use.
I used OsmAnd for a long time, and it's a great app that I learned how to use well. And while I do miss some features (most notably the Wikivoyage integration for offline travel guides), ultimately the simplicity of CoMaps makes it much more pleasant to use for the thing I mostly use it for: getting around cities.