As someone who first switched to lemmy, and then quickly switched to kbin due to rampant de-federation in the lemmy world, I say I just first heard about lemmy.
But, Kbin is much more modern, and spectating the changes done in the last days alone, it moves fast and attracts many developers while all lemmy 0.18 did was breaking federation with kbin. I can fully recommend the switch to Kbin, its that good.

About Tildes, it seems to be more of a clone of Digg in the old days.

It's for all these reasons I'm fascinated Kbin hasn't received a larger influx of new users. It seems truly the easiest to easily switch from Reddit, you just need a browser.

Well, there's the thing, you need a browser. You'd be surprised how many newer Reddit users access the site primarily or even exclusively on their phones, and who tend to use apps rather than their mobile browser.

I use kbin primarily on a browser (firefox) on mobile. My only complaint is the side menu options for aubscribing/blocking being located at the bottom of the page instead of higher up.