I cannot agree both bitcoin has entered into mainstream and main stream adoption is the indication of early adoption stage. Early adoption phase is something we cannot figure out with the help of price level nor age of bitcoin. Because, if you consider 10% of peak value and life time of bitcoins then I guess we are still into the early stage of bitcoin ecosystem.
Because in my speculation, I am expecting bitcoin to value around one billion dollars and may serve human race for another 10 to 20 centuries. So, we are not even 1% of those parameters.
Moreover, mainstream cannot indicate that we had passed early adoption phase of bitcoins. In my view, main stream adoption is needed to end the early adoption.
It is about being known or heard, when you are at an early adoption stage that means there are many people who do not know about it, but right now bitcoin is not at that stage, you may or may not have some people who do not know about it at all, but that number is very low right now, 90%+ of the world heard about it, probably closer to 95% of the people as well.
I am not saying that many people have bitcoin, I am just saying that those people are aware of it and that is the important thing, people should be just aware of the fact that crypto exists and we are already beyond that. This is why I agree that we are out of early adoption stage, we are still not at the advanced levels, we are still getting adopted everyday in many places, but it is just not early, it is probably beyond-early or something, I do not know what it could be used, it is not further ahead, it is still early but just not too early like it has been 2-3 years ago.