Fully agree, I don't get this worldview where anything that does not take the undisputed nr. 1 spot is to be considered a failure.
I created my Twitter account ~10 years ago, I had barely any noteworthy interaction on it. I used it mainly to follow interesting accounts and people, but it never managed to convince me to tweet a lot myself.
On Mastodon I am more active than I've ever been on Twitter. This is of course also a side effect of it being new and exciting for many people. But what exactly do I get from Mastdodon becoming gigantic? All I need is a healthy, active userbase.
I don't care if Mastodon ever "overtakes" Twitter, all I care about is whether Mastodon can cultivate enough active users to stay healthy.