Oh I definitely agree with you that I hope WhatsApp is the past. I sure do hope for something open, not sure if RCS is the solution here though.
In any case, iMessage share the exact same issues and also adds the issue of locking you to a single platform, so at least WhatsApp solves one issue that iMessage has.
In any case, iMessage share the exact same issues and also adds the issue of locking you to a single platform, so at least WhatsApp solves one issue that iMessage has.