Funny I've never seen that, but I switch around from time to time. Because none are perfect unfortunately.

Startpage uses outside search results, but should be very secure like DuckDuckGo, and better certified.
Qwant is AFAIK more independent, and I like the layout better.

Both give pretty good search results IMO, but are somewhat lacking in map/geographic searches. For instance searching "Angola" could result in a restaurant in London. Just as a hypothetical example.
So I do use Google maps too.

qwant = 95% bing results, startpage = 98% google results. They are slimmer. They don't keep your search history or ip address. better for privacy but not much better for search results.

That's a bit disappointing, I thought Qwant had their own search. I know startpage used Google originally, but I wasn't sure if they still did.

Start page was out too afaik