I really prefer to run my own local instance of SearxNG, but when I can't (but still want a wider net of search results), I use one of the public instances at
https://searx.space/
Also, Firefox allows you to use the @ symbol to search with a specific engine. I usually add in some mix of, GitHub, Odysee, Yandex, Invidious, Youtube, Mankier, Arch Wiki, Wiby, Marginalia, Startpage, Brave, and a public instance of SearXNG.