If your WhatsApp loving friends need some convincing is switch to Signal I would tell them:

• Signal is more private than WhatsApp.
• Signal has a "stories" feature similar to Instagram or Snapchat... I think, I don't use that sort of thing. They added it in the last few years and I've been wanting to try it but like you my friend group is mostly elsewhere apart from a growing few who have had enough of Meta's BS. The Europeans and South Americans I know are extra embedded in WhatsApp because SMS stopped being used there much earlier than in the US.
• Nearly no spam! I can't recall having ever received spam on Signal. WhatsApp is full of it.
• Signal is a simpler app. If you have anyone older, anyone handicapped, anyone with a traumatic brain injury, etc. in your friend group, Signal is much more sensical and easy to use. WhatsApp is cluttered and has some baked in AI slop.
• Built in scheduled sends. You can press and hold the send button and choose when your message will go out. This is great for a night owl like me who doesn't get around to answering until everyone is asleep and also doesn't want to wake anyone up.

Hope this helps, and let us know how it goes,many of us are trying to do the same thing. How big is your group? Can we help you make a slideshow presentation? :D