All tenants are not equal before the law

Here are four scenarios comparing two tenants who do not benefit from the same rights, although they have, in theory and for the purposes of our demonstration, completely identical housing. One lives in a 4 ½ dwelling in building A, while the other one also occupies a 4 ½, a carbon copy of it, but located in building B next door. However, the rent of the apartment in building B is much higher and the tenant is not entitled to the same quality of service. Why? One clue: R-20 ACT regarding regulating maintenance, repair, and renovation, among other things.