And those who were stubborn enough to keep looking at all options despite what could easily feel overwhelming to a non-tech user.
I am not very tech-inclined, so trying to understand the fediverse as a whole felt like very deep water, and lemmy really didn't do any job at all at explaining what it was I was committing to by choosing an instance when I didn't even know what instances were and had trouble finding out.
Since Lemmy was and is by far the most mentioned alternative and I found it too anxiety-inducing, it's mostly stubborn desperation that brought me to kbin. Which says nothing to how much I'm genuinely enjoying it here, to be clear, I was just relieved to have a simple option at that point.
Being made anxious by a new platform isn't great and I would guess that most people who didn't like the experience they had with Lemmy didn't bother clicking other links that would take them to the same fediverse. They're likely to assume they won't enjoy that one either, and resign themselves elsewhere.
So kbin naturally got fewer users just by word of mouth, and then the necessary brief isolation didn't help either when people were still getting comfortable and testing out different accounts. I don't particularly mind it other than those rare times I'm accidentally excluded, either by a question addressed only to Lemmy or their recent version of r/place disappointingly being incompatible with kbin.