Which big US social media company operates without some form of involvement with the ADL?

This isn't a conspiracy, the ADL openly admits and is proud of their involvement in censorship.

Here they are bragging about their role in youtube censorship:

https://www.adl.org/resources/press-release/adl-applauds-goo...

Google search results censorship:

https://www.adl.org/resources/news/can-google-search-be-used...

X may be the one exception, though I note that the "advertiser boycott" was ended when Musk made trips to Israel, was photographed next Netanyahu's atrocity propaganda prop pieces, next to Ben Shapiro, etc.