The Bitcoin revolution started at the moment the network went live.

In the end, we should be happy that we won't ever come to a point at which the mass (as in hundreds of millions of users) drop their weight on Bitcoin. Fiat's coexistence makes sure that people have the ability to choose which currency works the best for them, and in some cases that's Bitcoin, and in other cases fiat.

Bitcoin's main selling feature is being decentralized, but that's also it's main weakness when it comes to mass adoption. Let the mass use Bitcoin strictly as store of value and use fiat as money, and the rest will happily utilize Bitcoin as money through LN. I think that's a fair enough balance allowing Bitcoin to remain the decentralized safe haven for as long as realistically possible.

That was the most realistic side of the story.

The less realistic side of the story, but most preferable outcome, is that satoshis become units of value on their own. Gold had that status at a given point, and Bitcoin might gain that what Gold lost back then. I know most people can't even imagine Bitcoin reaching that state, but we have enough historical evidence that Bitcoin has always been underestimated and has done that what the many didn't expect to happen. I'm quite optimistic yet realistic.