Recent intrusive changes in the privacy policy of WhatsApp (including the sharing of never before seen amounts of unencrypted user data with the parent company Facebook) have prompted a mass exodus of WhatsApp users to the secure and open-source alternative Signal. I have been hoping for a change like this for years. I wrote a non-technical blog post about the problems with WhatsApp in detail, comparing the advantages and disadvantages of other messaging apps as well.
You can help educate people though. Try to teach people to use their computing devices instead of being used by corporations. Fewer and fewer people nowadays can really admin their devices, both from a technical and an educational viewpoint.
Ask around what the problems are for your family and report them as bugs or vote (don’t write +1! Use the emoji reaction feature on Github etc.) for them on their respective bug trackers. For my mom I found out that she doesn’t have issues with the software itself but can’t find or doesn’t know how to use the features it has. Fluffychat is an example of a slightly better Matrix client on mobile than the “default” client Element.
Stickers are already implemented in Element and other clients via third-party integrations, but they’re being reworked to be included in the base Matrix specification.