Generally laziness helps.
If you host a system, then you have to dedicate resources to maintaining it, which quickly escalates to lack of interest.
If you pay someone to host it, you get to spend your energy on things that you're interested in.
If you can find people to pay you for things that you're interested in, but they just want fixed, you have a business.
So, be conservative in what you host and frivolous in what you outsource.
Note that this says nothing about FOSS. since that's about a related but different concepts.
From a FOSS perspective, be frivolous (as in, do lots) in your bug reports and patches, be conservative in which projects you own.