If that were going to happen it already would have. So what's stopping it? There isn't a studio or art school out there that doesn't know about blender or know that it is free. Most of them still prefer to spend their money on licenses to more efficient software. Not saying blender is bad, just that there are better more efficient options. We've had this debate a number of times before, I'm not going to rehash it. The majority of clients looking to hire CG artists - in house or freelance - will not hire an artist that isn't proficient in Autodesk and Adobe software. Most won't even bother to look at your portfolio. Now maybe that will change in blender's favor in the future but for now it's nowhere close to happening.

As for Unreal... Unity still seems to have an edge over them in popularity, and their pro version is still premium along with royalties. Unreal was free a while back, before they briefly took on a pay model, which seems to not have gone over so good for them, since they decided to go free again. In fact, if I remember correctly I think it was Epic that started the "give the engine away to indie devs" trend some years ago. I haven't used either of them enough to give a personal opinion on which I think is better, but I have both installed.