Users who don't directly pay for a social service where user content and interaction is the business are still valuable. They share videos around, they comment, they contribute to it being the place where everything is happening. There's a reason all these tech platform companies spent so long in the honeymoon phase of monopolization. Without the network effect of people on their platform, they have nothing.

They still need a way to overall make profit from their users, but they aren't losing nothing by losing people who adblock.