Kind of agree, kind of don’t. A lot of companies also bolt on as many features and integrations to their products as they need, to close sales or just because they think it will help expand their potential customer base. A lot of FOSS is maintained by people who don’t want to spend their free time shepherding some code they wrote turning into everything-software either.
There is a particular failure mode in FOSS though - normally in businesses, prioritizing new features is done on the basis of how it will ultimately affect revenue (or reduce costs, simplify things, reduce maintenance burden - still money at the end of the day). For those FOSS projects that are open to new features from randoms, those individuals are mostly adding features they individually want, and the amount of investment in those features is limited mostly by their level of personal interest. So you end up with a set of features that is more stochastically chosen, and some unimportant or minor features may have a huge amount of complexity/configurability/feature-specific code because one person needed it.