I think there's a fine line between helping your team grow and the sorta annoying self promotion I've seen people do in overly broad slack channels.
One is actually helping and the other is making yourself more visible to mgmt for promotions.
We work in very different places. Wherever I've worked, the guy who knows all these tricks is not the guy getting promoted. Senior management doesn't care about your shell or scripting skills. Sure - they make you more productive, but at a very local level (may be good for a single promotion early in your career).
Most senior engineers I've worked with have forgotten all these tricks, and they actively tell you that while you should try to get better at these things, career gains lie elsewhere. Focus on things with higher impact.
I rather think the opposite. People who share tips and hacks are genuinely trying to help others, while people who hoard information are competing on an individual basis without regard for team.