If youre a penniless indie dev at the dawn of your career, it makes perfect sense to download blender and gimp and binge-watch youtube tutorials.
But if your plan is to work for the big studios on the major titles, then the simple fact is that there’s an industry here and that industry has standards. Literally everywhere that offers formal training will teach you how to use Maya because its the standard software package of the 3D video game industry. I really hope blender takes off and becomes the go-to package of the industry, but it will take years yet.