Email, docs, music, maps etc have reasonable alternatives and you don’t depend on others to switch (a gmail user will receive my email from tuta). But with WhatsApp either you conceal and use it or you just don’t talk to people (tried convincing them to switch to signal and it simply doesn’t happen)
How do you deal with it?
Thats the neat part, you dont
Unlike all the apps you named it, “users” is what make it still alive to this day
You gonna have to use it with Signal if you want to use Signal that much, or just dont