It failed because achieving it wasn’t easy or cheap enough for consumers, wasn’t profitable enough for investors, and was too much of a threat to entrenched corporate/state interests.

I bet the answer is greed and rich people

https://removepaywalls.com/4/https://www.newscientist.com/article/2515030-why-1-5c-failed-and-setting-a-new-limit-would-make-things-worse/