This predates the OGL. Lots of people don’t like D&D 5E. In my case I just don’t like the rules for AC, hit dice, hit points that go up (AC should go up), and Vancian magic are all reasons to avoid D&D.
Is it still Old School Essentials? Is that the standard response to, “What else is there?”
I would steer people to Palladium Books Fantasy, especially 1E. Sure, it’s got quirks like the stats for shields are not in the equipment section, but written in the proficiency skill description. 2E continues that oddity too, because it’s tradition?!?
Or lots of OSR games that are free. Dragon Warriors is another I’m starting to warm up to, and currently pay-what-you-want on DT-RPG.
I don’t think this question has changed. Avoiding a game with the old 1.0a OGL in it seems petty, as that still isn’t a thing. In fact, I say get your alternate games now before they go away.