Equality is not a self-interest
It's not even a group interest. Equality, in an economic understanding, is an absolute state and can be measured. If you share a jug with lemonade, there is just one equal way to do it. But let's be honest, even if homo economicus is a theoretical construction that does not match reality, self-interest is part of the personality of all individuals. Equality can coincide with self-interest in particular circumstances, and individuals may desire equality from a moral position. But when push comes to shove, the well-being of ourselves and those who are close to us is more important to us than others. Equality cannot arise from a subjective perspective, but only from one that is panoptic, where humanity is viewed as a whole. In the sum of all single perspectives. In the end, this is a moral/ethical matter that the individual can only strive for but never expect to live by, to the full extent.
Radical equality, as proposed by commensalism, must, therefore, be guaranteed by legislation that applies equally to everyone and is elevated above daily parliamentary politics and the special interests of different groups. It should be part of the Constitution. No party or group representative should drive the struggle for commensal equality, but it must be a popular movement that, through strikes, activism and advocacy, puts pressure on those in power to implement it.