My take (as a subscriber) is still that the majority of information I'm seeing is assimilated and distilled from the more mainstream sources, but I'm possibly underestimating how much comes from their own indexes.

I will admit that for news I tend to use the !gn bang to jump straight to Google News as it tends to be a more complete feed than Kagi's news tab, so wasn't thinking about TinyGem. But I'd also forgotten completely about Kagi's "Small Web" initiative for indexing non-commercial content that's not interlinked enough for other engines to prioritize it. I believe that's what Teclis (and possibly TinyGem as well) concentrates on.

IIRC, the few times I tried routing searches into that index I didn't find much, so I set it aside, but that's probably because I'm usually searching for more widely-consumed content.