Tiktok optimizes for momentary engagement and fast-paced social content. It turns out that's a niche that people want filled, and the rapid bouncing of ideas between users has created some very fun content which sometimes escapes containment so I can watch it. But not everything is going for the same goal, and honestly I wouldn't be surprised if more than a few players could really get in on that space. For other use cases, customization may well win out over a totally frictionless experience. A search engine is a tool, and benefits from more options much more than Tiktok does.

TikTok's purpose and use-case is completely different from that of a search engine.

Tech power users are still a niche in virtually every use case except maybe HN

Tech power users (and power users in general I would say) might have more money to throw at the problem. "Nicheness" isn't necessarily a bad thing if your niche is profitable. I heard somewhere that power-grid-scale transformers are have insanely long lead times so the industry most be pretty niche (when's the last time you needed one of those?) and yet I think we can all agree that the equipment is valuable and I bet those manufacturers are making bank.