How to make decisions for which Apps to use?

I appreciate your reply!

I think you’ve been the only person to understand what I’m trying to say in regard to using a dedicated Linux firewall distribution that’ll protect a user’s home network, but this falls apart when there’s an App on a Windows PC that’s transmitting data about the user back to the malicious author on the Internet. It could be something as benign as an app for reading PDF files that brings the user’s security crashing down despite having a dedicated Linux firewall distribution.