P50 TRACON reported a loss of separation between two aircraft on final.

Narrative

Aircraft X was IFR for Runway 26 at PHX. Aircraft Y was IFR for Runway 25L at PHX. Both aircraft were on 30 degree intercepts for their runways and cleared for the visual approach. Aircraft X went through final at almost the same altitude as Aircraft Y on the parallel runway. Separation was less than a mile and maybe 100 ft. Even though both aircraft were cleared for the visual approach and given 30 degree intercept headings they became dangerously close. The operation is completely acceptable in the 7110.65 but is very dangerous. This happens regularly with parallel runway operations at this facility.The 7110.65 needs to be changed to mandate standard separation until aircraft are established inbound on the final approach course. According to the 7110.65 paragraph 7-4-4; nobody is responsible for the IFR separation of 2 IFR aircraft. This operation is extremely unsafe and used at many busy airports with parallel runway operations. Many of the final approach courses are over highly populated cities. The risk of a catastrophic event is high.