1. You can monetize it.
2. You can sign up for affiliate marketing without any boundaries.
3. You can create courses on it.
4. You can start selling on it.
5. More freedom, less restrictions.
6. It will not get blocked or deleted if you are being successful which happens often.
7. Freedom to customize more, add plugins, create lists.
8. It is more professional to have your own domain than say a wordpress or wix attached to it.
9. You can advertise on it or promote a product on it more professionally.
10. You can add Google adsense on it.
11. Yoo have higher chances of getting accepted by adsense program.
12. You can add Bing ads and yahoo ads.
13. You can start your own company.
14. More privacy and more protection.