Well I think it's a balancing act. Ultimately, can you prove to me that something like DuckDuckGo or Kagi aren't ran secretly by NSA as a sort of honeypot? So it's the same with Uruky. They are a company and I doubt anyone can prove to you that they're not for example behind your back selling your data to some broker. You just have to feel their vibes and finally take their word for it.
If you can't trust then stick with open source and self-host, that is the only way. Read the interview that I linked to, that got me to try them out.