Honestly, I couldn't get my dad to use signal. And personally I think that signal is lacking in a lot of features like a smartwatch app, ability to send messages through a voice assistant, among other things because of the fact it prioritizes security and privacy over everything else.
WhatsApp just recently got an app for Wear OS
Meanwhile, Mozilla refuses to implement feature parity with chromium in certain places they seem to be too invasive.
Also, chromium browsers can block ads.