Source Identifier Sanitizer от Oathbound

This add-on simply takes the link generated by the YouTube video page whenever the Share button is pressed and sanitizes it by removing the "si" parameter from it.
This parameter, called a Source Identifier, is superfluous and serves only to extend an otherwise shorter URL and to potentially compromise your online privacy.

You can also manually sanitize links by clicking on the add-on icon and pasting the link in the appropriate field. This method supports more website links, such as Facebook and Instagram Reels.