Facebook is a big company and one of the most famous social media website. Even my neighbor's dog has an account on Facebook. So, it won't be surprising that many will but and support it. This is also a good opportunity to introduce cryptocurrency to the public since many still do not know what is it aside from bitcoin. There are still people that I know I'm real life that only knows about bitcoin. With this great example, people might see crypto in other light.
It is right that there are a lot of people who are using facebook but there are some points which are that firstly the owner of facebook is facing some issues from his government in starting his coin and other point is that many people who will not need any payment system in facebook will not use its coin and will just use facebook for connecting to other people.
Honestly, Facebook is the most famous social media platform as of now and I can say that it has the most number of users as of now. I can say that if libra would become successful there are lots of people can use it since Facebook has so many scopes because there are people who earns because of Facebook such as streaming, there is also a marketplace in which they are selling and buying, and maybe they can use libra coin when buying those items. There are also times that we can send load or money using messenger wherein it is a messaging app that you can also send money.