Interesting results... I think that Bitcoin SV is less known by the few masses that gain interest on crypto, it just popped up not so long ago and people don't care that much about "one more bitcoin"...
Concerning Binance coin, I think it is also natural as it has a limited interest for people not using the exchange... for these it becomes only speculation
Both BCH and BSV are total shitcoins that would have no market cap if not for the word Bitcoin in their name. They were early forks and gathered all the attention of people who thought they can make money with something made of the original valuable asset. In other words they bought a knockoff hoping that it would explode.
BCH has some google searches because of bitcoin.com. Many newbies get lured there thinking it's the official site for Bitcoin but it belongs to the owner of BCH.
BSV relied mostly on Craig and not a site so it will always have less searches than BCH. Also BSV is not a fork of Bitcoin so it's a step behind BCH and with Craig's reputation in ruins without any chance catch up.