Are they though?
The official trailer Fallout 76 currently does have twice as many views (33 mil) vs Cyberpunk (16 mil), but it also has half as many likes (159k vs 358k) and nearly 3 times the dislikes (14k vs 4.9k). To me this suggests that Fallout 76 was more anticipated, but less desired than Cyberpunk 2077, which makes sense because Cyberpunk isn't another installment in one of the largest gaming franchises ever made. People weren't waiting for Fallout 76, they were just awaiting another Fallout game, and of those 33 million people a relative handful of them said sure this will work.
To be clear, I'm not knocking F76, I was actually just talking with a coworker earlier today who made a pretty good case for buying it, just saying I think the franchise is doing more to get those views than the game itself, and the responses of the people who watched both trailers seems that CP2077 was much better received/desired.