Track record is what makes them different from "young blood" that would want to take their place. When someone took part in leading the chain through many hardships, it adds to their value as a witness.

This one is really, really tricky.

Just by virtue of arriving on the chain first, many of the top witnesses were thrust into the position you just described, and rode it out, sure, but its more coincidence it happened on their watch and the timing of their arrivals that caused it, than prior experience.

There are MANY backup lower level witnesses who were here for those things, involved in helping mitigate them, code for them, whatever might have been happening.

You just couldn't "see" them, because they were merely mid-tier witnesses and don't get the notoriety or reach / visibility of people talking about them in posts or comments or weren't even witnesses yet at all during events such as "the forkening" or whatever.

And there are some non-20 who WERE top 20s then who aren't anymore, even if they deserve to be based on effort, passion, caring about the chain and people and so on, @TimCliff is a PRIME example of that. But he never played the pander-to-whales game so I suppose he eventually got shifted downward. I don't know. Maybe he burned out and let go a little, maybe real life got in the way, lots of possibilities for shifts over 8 years - not mine to say or speculate on.

But the fact someone was in place when a thing happened, doesn't mean they were there just on merit. MANY are and were, some others up there, not so much at all.

So its an interesting criteria, but one with a lot of vectors and considerations to be fully made into a "whole" holistic criteria.