Sure an ad blocker improves the experience somewhat. But I try to keep adversarial relationships out of my life. I don't understand why people want to normalize this.

Only in Firefox or user-friendly browsers, otherwise uBlock Lite is free for Manifest v3 browsers

Both block all Google search ads fully and seamlessly.

but they don't block sponsored/seo-gamed articles, no?

Neither does Kagi, at least fully. Customizations help a bit until you need to search for something outside your usual focus areas. Anyone who claims to have created a search engine that truly surfaces the best links and ignores SEO is lying to you.

That covers half of it, and indeed I do also rely on community and personal block/deranking lists for SEO spam.

Does ublock or ddg etc block sponsored results?

iOS Firefox doesn't support extensions nor does it have proper adblocking.