The last time I tried to make video chat work with people, we dived between jitsi, facebook messenger, zoom... until something worked well enough. what are people using here now? Jitsi? Google Meet? Whatsapp? Facebook Messenger? Zoom? Skype? Facetime, somehow? The builtin thing in matrix that used to be jitsi but I think they updated it? Microsoft Teams? What?
Really? Are you a web developer? Reporter? The only people I know on Signal are a reporter, who hates using it but needs to for sources, and a friend from undergrad (a tech school) who... probably doesn't use it anymore, I haven't actually been in touch with her.
Literally all of my friends use it and since recently even my parents and family. But if you have WhatsApp, Viber, Discord, WeeChat, Kik and Signal... people will say... ah I'll use Viber to reach you and leave it at that. You have to get rid of others and then people start moving.
Likely just not in the US. Many other countries never had unlimited texting plans, so messaging apps that could bypass SMS became very popular when they came about.