I mean, we could structure our society so that everything wasn't arbitrarily gated but that would be gasp socialism.
Also, Telegram and Signal are already open and can be bridged from anything to anything so yeah, we should force Messenger and Imessage to accept, at a minimum, bridging as well.
To be honest, I personally agree that we should be forcing at least some of these things for the common good (and, to the extent necessary, funding them with significantly-more-progressive taxes). My point is primarily that it's not particularly logical to single out Apple for this treatment if that's your principle.
Good to know about Telegram and Signal—I don't use or know much about them. IMNSHO, my argument still holds even removing them from the equation.
Also, Telegram and Signal are already open and can be bridged from anything to anything so yeah, we should force Messenger and Imessage to accept, at a minimum, bridging as well.