Half of these services are run or maintained by private companies... This is fundamentally something that we can't trust.. trusting our security and privacy to an opaque organization. Any tool needs to be open source and transparent
The unfortunate reality seems to be that quality open source versions don't exist for a lot of these. I'd love to hear about alternatives that you know of though.
It doesn't matter privacy-wise if service without end-to-end encryption (like Burner, Pastebin or DuckDuckGo) uses FLOSS or not.