From my point of view, we need someone huge to announce Bitcoin acceptance, like some from top European countries. Or wealthiest company like Apple, Amazon, Microsoft or Alibaba Group would buy a large amount of Bitcoins. Or worlds wealthiest persons like Bezos, Brin, Gates or Buffett would announce they make large investment in Bitcoin. I think that might trigger price to go up. We need a strong price push to provoke huge growth. Without it, with natural price growth, it will take a lot of time or unknown amount of time to reach new ATH.
Well, I know one thing that doesn't need any of those that would trigger Bitcoin price to rise and always have the possibility to hit a good ATH. And, that occurs every 4 years. You know what I mean? That's not an "unknown amount of time right?".
If by fortunate chance, If any of that you mentioned happens then that's a good thing for Bitcoin. Sure it will take Btc to a good pump but still no guarantee for a new ATH.
Nevertheless, we have seen Bitcoin pumps unprecedentedly many times, like we have to find a good reason for the pump.