Google's John Mueller was asked if there is such a thing as having too many outbound links, even if those links are natural. John said "I'm not aware of anything like that." He did add that maybe there is a situation where you are lacking content because you have so many links, i.e. like directories.
But in general, there is no sort of penalty for linking out too much. In fact, outbound links are not a ranking factor. I mean, if you link to a lot of bad places, you can get a manual action from Google but having tons of outbound natural links won't be something Google penalizes you for.
Here is the Q&A on Twitter:
I'm not aware of anything like that. Usually the problem is more the rest of the site (like when there's a lack of real, unique, compelling, high-quality content) rather than the links.
— 🍌 John 🍌 (@JohnMu) August 13, 2020
Forum discussion at Twitter.