There are good reasons to learn to use pacman: it is the superior package manager.
However, if you are using pamac and it works for you, are happy with it, who am I to tell you to use something you like less? 
Be aware that there have been countless reports of pamac breaking an update, or failing to completely remove packages and dependencies. These are fairly minor and not too common annoyances, so if you have no such experiences, and really like the GUI of pamac, I don’t think there is any point in trying to convince you not to use it.
You are not harming anyone by using pamac, so do what makes you happy 