Often times you can get a support for a stable OSS, and then you actually help the ecosystem by giving it resources
One way to make a system so incomprehensible that your customers absolutely need support is to make it configurable in a million different ways, and make the configuration invisible / opaque.
Example:
"Why is this program doing this when I told it to do that?"
Answer: Because this file in that directory configure service A to do X, and this other file in that other directory configures the program to behave like Y if it detects that service A is doing X.
But the program does not tell you that via its UI; you have to read obscure documentation.
Yeah, and the way that's done is by refactoring things, removing buggy/deprecated things, and not adding any more new features/requirements... So, pick your poison, I guess? I'd love to go move on to the next job as much as the next person, but somebody still has to be paid to do those things. I don't see what the significant difference is there with free-with-paid-support, if you pay for it up front you're still paying the same cost.
Yes you can. You can spend some time to stabilize, and then add new features on top, then stabilize again if needed.
The distinction is cruicial.