The web is great. Hyperlinks are great. Being able to link to another relevant resource is great.
Please though, link for context not as content
Linking as content:
A: “How come we’re doing Y now?” B: “Because http://example.com/thisiswhy”
Now A needs to go follow the URL to get an answer
Compare with linking for context:
B: “We used to do X, but it had reliability issues for some of our customers – check out http://example.com/thisiswhy”
Don’t use a URL as your answer, comment, explanation etc.; use it as a supplementary aid. “Don’t Repeat Yourself” is for code, not for information.
If your content is just a link, you’re forcing the reader to go elsewhere to understand. Nobody wants to have half a dozen browser tabs open just to follow a comment thread.
URLs break; sites reorganise, posts get deleted, domains expire, and more. Nobody wants to sit there cursing at a comment that just says “Important! See #1234” in a project that has changed issue trackers twice during its history.
Write content that stands alone, and use links elsewhere to give optional context. Future readers will thank you.