Works as of October 2021, prevents the search bar from following as you scroll down the page
New YouTube Obnoxious Bar Fix was deleted due to: Report #18149.
Appeal submitted by the author:
My scripts are not commercial and don't mention any licensing. How else do I "comply with the terms of that license" other than linking to the original author's gist?
As a result of this appeal, a moderator undeleted this script.