ZAB Center Controller reported transmitter sites routinely fail and the equipment issues are not being addressed appropriately creating unsafe situations. An additional site is needed to ensure ATC communications.

Narrative

We had our FST transmitter site stop working. Facility management only would declare ATC limited; refused to declare ATC zero; and expected us to constantly relay through other aircraft constantly for everything. They constantly hide the severity of the situation; how unsafe it is; and Controllers are intimidated from saying ATC-0. This is a massive sector; there are mountains; this is totally unsafe and its going to get someone killed; because they actively refuse to declare ATC-0. Management wants to hide this and look good; they don't take it seriously; it's been happening for months. When you only have two transmitter sites in a sector that's 250 miles across and you lose one; its unsafe. Relaying and lost communication instructions are temporary and only meant for a limited amount of time. They want this to become standard practice. This is called drift. The facility management is actively encouraging drifting away from safe practices.We need to have 3 or 4 transmitter sites in 63/20. We need to assume that losing transmitter sites is going to continue in the future and have 3 to 4 sites so it stops impacting the operation and endangering lives. We do not have redundancies built into the system. We have multiple frequencies but they're only located at two sites; that's not redundant. We need both frequencies at ELP; MRF; FST; CNM.