Air carrier Captain reported there is a lack of lateral separation with SFO's procedure of pairing aircraft for landing on the parallel runways; leading aircraft to fly wingtip-to-wingtip from the FAF to landing.

Narrative

Approach Control; 135.65; controls aircraft arriving from the east and west; and coordinates those arrivals; during VMC; and pairs these aircraft for landing. In the distant past; on the approach plate for the parallel visual approaches; it stated ATC was to provide a minimum of 1/4 mile lateral separation. Sometimes this was followed; many times it was not followed and the aircraft end up wingtip to wingtip flying; from the FAF down to landing. This is not supposed to happen and should not happen. The margin for error is minimal with wingtip flying. Overshooting winds in either direction could easily lead to loss of separation. In addition; it is beyond distracting for both PF and PM to have to constantly look at other aircraft to ensure separation; all while trying to maneuver and configure on final. SFO is now the only airport allowing the TA only option to avoid descending RAs; at night; generated by the following aircraft. And if the lead aircraft is not in TA only; the chances of an RA are very high; because Approach Control is still vectoring and adjusting speed of both aircraft to put them as close together as possible. I cannot believe we have not had a mishap with this practice. It is the best example of 'normalization of deviancy' I can recall. Wingtip flying on the final segment has become so common everyone is accepting it as normal. It shouldn't be normal at all and shouldn't happen ever. The new 28R approach attempts to minimize the RA only; with the final intercept not occurring now until 500 feet or so. There won't be an RA below 1000 feet so it does accomplish that goal; but it is not helpful at all in mitigating the potential of mid-air collisions when; at 500 feet; the aircraft on 28R is maneuvering to line up with an aircraft on 28L; and they are abeam one another. Strong overshooting winds could easily result in the 28R aircraft blundering into the path of 28L. I've seen many overshoots over the years and we've been fortunate there have been no accidents.