There’s always Blender… It does 99% of what you’ll need to make game assets. Some things might not be as easy or elegant, as they would be in something like Maya, but you can still do it. The UI takes a little getting used to, but Maya’s UI is already a clusterpluck and if you can get used to it, you can definitely get used to Blender. It’s free and has a million and one addons that can help get back some of the key tools you might need out of Maya.
Blender is also very close to releasing their eevee viewport version(you can try the latest experimental builds for it) and it’s basically a real-time wysiwyg view for PBR so you could even paint/texture/mask in the same program; without having to use substance painter or similar programs.