Oh, just found this! It's indeed Google tracking. Someone even asked ChatGPT.
"The sca_esv parameter is a piece of data in the URL that's likely internal to Google's system for tracking, sorting, or customizing search results. URL parameters like these are often used for various purposes including analytics, session identification, and to tweak the behaviour of the search. "
"Asking ChatGPT to brainstorm what sca and esv could stand for in the context of a Google search:"
https://webapps.stackexchange.com/questions/172215/google-videos-search-sca-esv-query-parameter-possible-tracking