This and because they see other users using this feature and then they feel the earge to copy it. There videos may not fit into there channels content and then need to create a seperate channel, to not allienate the viewers or and earn even more money, because one channel is seen as one persons business. They may use there second channel for stuff that may disable there channels monitesation. The best example is Unus Anus with Ethan and Markiplier. They used this channel to create memories, projects and stuff that youtube would demonitase to not effect there main channels and more.
To be able to make different content without the algorithm screwing them over because of the lower views
This and because they see other users using this feature and then they feel the earge to copy it. There videos may not fit into there channels content and then need to create a seperate channel, to not allienate the viewers or and earn even more money, because one channel is seen as one persons business. They may use there second channel for stuff that may disable there channels monitesation. The best example is Unus Anus with Ethan and Markiplier. They used this channel to create memories, projects and stuff that youtube would demonitase to not effect there main channels and more.