DDG uses bing and they filter results based on their biased opinion. Just give me results let me care about the rest! Brave has a limited index, plus not a huge fan of their crypto scam. StartPage gets results from Google and seems better than the above two. But Google itself filters results so not great. tbh, to get unfiltered great results try Yandex, they do have good index and seem no or less filtering. It would be great if SearX would provide a wrapper around Yandex, but AFAIK Yandex blocks bots and non-human interactions and it is hard to add SearX support. Kagi - I don't want an extra subscription.
For now, I think SearX/Whooper instances are good enough
I do like HoppScotch. Is there a reason why you may prefer Insomnia?