SearXNG is my daily internet search now +5 years; with YaCY Backends and else as fallback. I also build internal document search or RAG applications with this setup (SearXNG also support json results). However, there are some downer I accept because of privacy: 1. Its slower and the results are not that good then with others. But fast and good enough for most of my queries. 2. From time to time you get blocked on the duckduckgo, brave or whatever search and you must solve some captures. You can prevent this by getting and using API-Keys from them.

The nice thing about using your own backend is, that you can prio it in the results and for example, if I crawl the smallweb and other site important for myself, this sites come up first in the results.