Though Canva is easy to use & it's great tool but it will consume your time and effort & it's not necessary that everyone can understand desging or express there motive through one in world of social media design are becoming more important than ever before small details can change perspective yes if you can use Canva & you should. But you have to ask time consumed by it is it worth or not . Are you creative. Can you express your brand or feeling properly . Understanding of public perspective. Effects off colour & it's roll in marketing i don't think everyone can do it that's where designers come in if you can do it & if you have time you should do it but most people don't have time or understanding that's where designers matter