That really depends on your use case and how valuable web search is for your daily life.
I've personally tried Google, Bing, DDG, Brave search, and ChatGPT. Kagi is consistently able to find what I'm searching for more quickly and accurately than anything else, which has been very valuable for me in my personal and professional life.
It's easily worth the cost in result quality and time saving for me personally, but that doesn't mean the same will apply to you or anyone else.
As far as stand out features, there aren't really any that I can think of. It just gives me the results I'm looking for without any bullshit to wade through.
Not from the US but currently living here. I would say the Disability Act is the gold standard worldwide. The amount of consideration for people with a variety of disabilities that almost universally applies is exceptionally amazing. It's kind of shocking to see the dedication to adhering to that law while otherwise abandoning that portion of the population (e.g. Healthcare, SSDI, etc.).