Photoshop or any other open source software?

I use Photoshop whenever I am designing my forum to my liking, or making GIFs for my PPT in my classes. I think Photoshop is easier to use, and that I am contented with the features it has to offer. Others would also say their chosen softwares are easy to use because they have already learned it before mine, so I won't debate on that. For me, Photoshop is one user-friendly gfx software.