I recently noticed that comments are removed in many questions. Why is that happening? Most of the time, I found very good answers to my questions in comments rather than actual answers.
Is it a good idea to clear most of the comments?
From our help center:
Comments are temporary "Post-It" notes left on a question or answer. They can be up-voted (but not down-voted) and flagged, but do not generate reputation. There's no revision history, and when they are deleted they're gone for good.
Comments are meant to be temporary, and they are not intended as somewhere to put answers. Answers should be turned in to answers. See also What “comments” are not:
Comments are not for answers
Comments are not a substitute for answering questions. Comments cannot easily be searched, nor can they be edited for corrections or vetted with the community vote. There's no history, no reputation awarded, nor can they be 'accepted' as the best answer. They get little visibility but often keep users from posting proper answers because the question appears to be resolved… albeit, incorrectly. Further, those comment-answers will not bring new users to this site searching for the information. In short, you are hurting rather than helping the site, and your contribution is at great risk of being lost/deleted.
When I notice a lot of comments, I delete all the ones which shouldn't be comments because we get a lot of comments here, a lot more than we should. The only comments I tend to keep are:
If I have a little extra time, I will edit the answers to clarification questions/the additional information provided in a comment in to the post, and then delete the obsolete comments.