Share knowledge? I don't think anyone here is arguing against that in any way (or conversely arguing for hoarding knowledge).
The concern, one I share, is where the sharing has to happen publicly "every day" - so no matter how trivial, useless, niche, overly-specific the tip is (whatever, the list isn't exclusive), someone shares it.
That's the part that's not sharing knowledge for the benefit of others, but rather self-serving. I might even go so far as to say self-serving doesn't even need to be selfish; the person might genuinely believe they're doing good, but even there, self-serving.
TLDR: Share your knowledge, don't make sharing something every day, even when you don't have something valuable to share, your target.
PS - if this note irks anyone (are routine maxxers a thing?), make the goal to learn something every day, then share where appropriate.
Offering to teach someone something proactively? Sure, go ahead.
Sharing stuff freely when asked and arming someone with the tools to investigate further? Amazing!
Treating a public channel like ye olde facebok wall? Mildly annoying.
Every team/department/org/whatever should have channels everyone should subscribe to, and channels individuals set up that are optional for everyone. The appropriate way to handle this is for the OP to write a few tips once in a while in the public channel, and if people seem to like it, announce that all future tips will be in that channel.