It is interesting just how much of a game-changer (pun intended) the Open Gaming License was in the industry.
When Wizards of the Coast bought D&D from TSR, they didn't
have to give us an open license. Nobody asked them for one, it wasn't a requirement of the purchase agreement (as far as I know)...it was a rare and unusual thing to do. I imagine their lawyers were scratching their heads about it.
But it saved the hobby, skyrocketed their brand's popularity, and changed the tabletop gaming industry forever. It was so successful and so important that when they tried to replace it with 4th Edition's GSL, or tried to change it 3 years ago, the entire industry pushed back. And now, like
@darjr demonstrates above, it has become the expectation.
Time will tell if having an Open License will be as helpful for smaller game shops as it was for Wizards of the Coast. That kind of success probably takes more than just an OGL to get third-party publishers to climb aboard...you need visibility, brand recognition, a massive fanbase. Critical Role has a better shot than most.