The problem with Signal is that you have to trust them instead of choosing a host that you trust or hosting a server yourself.

I use the Apps TC (Tracker Control) and “open in whatsapp” from Fdroid. The first one blocks some tracking domains and also allows you to cut the internet connection totally. The second one allows you to open a contact in whatsapp without giving whatsapp any data except for the phone number. This is necessary because my android version doesn’t support work profiles yet. I think in normal operation all of your contacts will be uploaded to their servers.

To give whatsapp even less data you could try to get a second phone number which you can get rid of after deleting whatsapp. This way it will hopefully be harder for them and others to identify you later.

I agree vut I think you missed my point. You said it’s easy and I disagree with that. It may be a simple concept but it’s definitely more work on an everyday basis and you need to spend a significant amount of time and effort on learning and preparing all of that. These are significant barriers.

It seems to me like your rules might protect me from known threats (or not). But I don’t think it is easy to protect against unknown threats. At least when the advice is not using popular technologies and people like journalists necessarily need to use popular communication technologies. Also they may not be able to explain everyone of their contacts that they can’t open any links or documents.