Apologies if you already know this but there are tons of different instances of searx hosted by different people.
It’s possible the speed issue is related to the specific instance you tried, do you remember what it was?
Here is the list of all them: https://searx.space/
As I type this I realize I’m probably just not sensitive to slowness since I use tor for all my browsing lol
I self-hosted it, and used it for years and liked it. But the results take 3, 4, 5 seconds to come in as you wait for it to run the search on all the different engines. I just tested searx.be above and found the same thing.
When I use any other search engine, I get results in half a second or less. I know it’s only a few seconds but it’s definitely noticeable when you use a different search engine.