Thanks. After reading this and also realizing it'd be better to use a meta-search engine rather than a normal one because of the aggregation of results from different search engines, I am shifting to MetaGer. I find it's results better than searx.
Also, would like to say if you have TS;DR extension installed, it has a search engine: TS;DR Search which is an instance of searx and can be set to default in firefox (which I personally use) coz firefox doesn't show option of searx to be set as default search engine.
Update: Sorry I've reverted back to DDG. MetaGer searches are too random and change (right in front of my eyes) even after the initial results are shown.
For example, if I search for "esd windows" in https://metager.org, the first result "Should I delete ESD Windows..." changes to "ESD West Windows". In reality, I actually wanted the former but the result changed and the latter became the first result even after not displaying it after first time querying. For me, this is unacceptable and indicates manipulation (for whatever motive).
So, back to DDG. Search results are comparable to meta search engines (I've now realized). I'll put up with whatever problems it has for now. And man I miss the keybindings, made my life less painful.
I've moved to SearXNG since this submission, and it is just great (for my mostly IT queries), so if you say MetaGer is even better I am pretty curious: I see they have an English version https://metager.org (great), but I don't get what you mean with your second paragraph: the "TS;DR extension"
By the way: I've just discovered that you can set a custom search engine in Firefox without the extension: just right click, see https://metager.org/plugin and it works for searXNG too :)
Also, would like to say if you have TS;DR extension installed, it has a search engine: TS;DR Search which is an instance of searx and can be set to default in firefox (which I personally use) coz firefox doesn't show option of searx to be set as default search engine.