I think part of the problem is that 5e is so pervasive and baked into the "people who play TTRPGs" population that you need to sell them on why 5e isn't good before you can get them to consider why your alternative is good.
Frankly, I'm a White Wolf die-hard. I love Exalted. I love Werewolf. I love Mage. I tolerate Vampire. But as soon as I show someone a set of d10s and try to talk them out of the idea of "Leveling" they get scared and run back to the system they're familiar with. I also have a special place in my heart for Rollmaster/Hackmaster/Palladium and the endless reams of % charts for every conceivable thing. And then there's Mechwarrior... who doesn't love DMing a game where each model on the board has to track it's heat exhaust per round? But by god! The setting is so fucking cool! (Yes, I know about Lancer).
I will freely admit that these systems aren't necessarily "better" than 5e (or the d20 super-system generally speaking). But they all have their own charms. The trick is that selling some fresh new face on that glorious story climax in which three different Traditions of Magi harmonize their foci and thereby metaphorically harmonize fundamental concepts of society is hard to do on its face. By contrast, complaining about the generic grind of a dice-rolling dungeon crawl is pretty straightforward and easy.