DISCUSSION: What are the best ways of organising knowledge-sharing/storing in tech firms? (i.e. Confluence is trash, what are the ways we can do better?)

I have personally had such a terrible experience using Confluence. It is truly a black hole where you document something you've done only for it to be lost forever.

My question is: What are better ways of structuring knowledge-sharing in tech companies?

I feel that if a firm nails it, their productivity will shoot through the stratosphere. Imagine being able to instantly find out whether someone has already implement a library you need?