Totally valid. For me the killer feature is being able to change the weights for various sites, making it so websites with content that's not useful to me or I don't like don't appear^[e.g. apple.com, facebook, nypost, quora], pinning websites that I consider best-of-class for their relevant searches^[e.g. wikipedia, the ffxiv wiki], and prioritizing websites I do like, but aren't always the best answer^[e.g. opencritic, speedrun.com, cbc, w3schools, github].
They also have a "Lenses" feature that lets you make your own search lens (like I have one for Lemmy-only results), but I've not really had much use for those.
The regex redirect feature is another massive pro. I hope they bring it into Orion as well.
I already use Stop the Madness for this, and probably will continue to as it’s a more global solution, but having it built right into the search engine at least shows they’re taking real steps to hand control back to the user.
Oh ya I use that as well, to turn Youtube results into Invidious, reddit into web.archive.org/save/, twitter into nitter, tiktok into proxitok, and AMP results into normal articles. It's nice because, since I use kagi on my phone, it reaches where extensions don't normally.
I'm pretty sure there are browser extensions that already do this for you on Google. You can do it manually on each search but that's obviously cumbersome. But browser extensions are basically what you're describing and still free
It's cheaper to just run SearXNG instance. People claiming any new search engine is better than established ones are hallucinating with their anecdotes.
It appears a bit more difficult than setting up the original Searx. I've been poking around in the code for SearXNG lately because I'm planning on migrating to it but haven't done any serious work with it yet.