because is really popular, most of the people will watch youtube and at some point they will see your channel, using the most popular social media always provide you a lot of discoverability but is important to know wich one, if you have or are working for a solid company and you use tiktok, most of the audience will be kids under 18, facebook and twitter you have a more mature audience that could acquire your service and then youtube that has a complete reach in audience for all ages and you can redirect them to your website or any other social media.