Above all, the thing that makes me stay is having creative control and freedom over how I do my job. I've done enough things to know how rare that is, and how frustrating it is not to have it, and what a blessing it is to have the trust of the people I work for and with. It's so important to me that I feel it as a different baseline state in my body.
But hey, thanks for all the great work here!
The answer to that is probably just "attachment disorder'. There's nothing wrong with stable relationships, and the way you describe your preferences sounds completely healthy to me. It definitely does happen in practice, even if it's not the default, so don't give up!
(I post not-a-mod comments semi-regularly, but they drown in the ocean of "if you'd please review https://news.ycombinator.com/newsguidelines.html and stick to the rules when posting here, we'd sure appreciate it ̶g̶r̶r̶r̶r̶r̶r̶r̶r̶r̶r̶r̶r̶̶".)
Don't worry about labels. If you like something, do it.
If you're doing it too much or if it's harming anyone, review it.
I do understand your feeling though, even the funnest situation can at some point stop letting you grow as a person, which is why a job you can also grow in is crucial. That and the creative control / independence you mentioned are both very important IMO.
Side note: many people seem to misunderstand why tech companies tend to seek growth. One of the reasons, even in non-startup companies, is that companies that grow mean growth opportunities for employees, which means better employees and keeping your good employees. Companies that don't grow tend to eventually lose their best employees, because there's literally no room for growth in their job.