Elon has been very dismissive about hydrogen at least a couple of times saying that hydrogen is not a power source, that is horribly inefficient and fueling car

Elon has been very dismissive about hydrogen at least a couple of times saying that hydrogen is not a power source, that is horribly inefficient and fueling cars with it is blatantly stupid. He also added that this will become evident to everyone sometime in the future. I'm not educated enough to understand if his statements are true or he's just defending the battery model because Tesla went for it. I also can not figure out why - if hydrogen is so obviously a fail - such a company as Toyota is betting on it. Is anyone available to elaborate on that in order to help me to better understand Elon's dismissive position on hydrogen as a fueling technology for cars? Genuine question, and thank you to anyone willing to ELI 5.