Wrong question to be asking.
A better one: why do so many of the homes SF has ACTUALLY approved in recent years trace back to Senator Wiener's bills?
880 McAllister: 2,300 homes (SB 593)
1064 Mission: 256 homes (SB 35)
1965 Market: 201 homes (SB 423)
1939 Market: 187 homes (SB 35)
730 Stanyan: 160 homes (SB 35)
681 Florida: 130 homes (SB 35)
2340 San Jose: 121 homes (SB 35)
2550 Irving: 90 homes (SB 35)
3001 24th St: 45 homes(SB 35)
SB 35 alone has streamlined 3,600+ homes in SF.
The broader context: State law can open the door. The city has to choose to walk through it.
San Francisco has indeed not built enough housing in recent years. But what we have built (majority of affordable!), would not have been built without Senator Wiener's efforts.
If we want to realize the full potential of Senator Wiener's work to become housing, City Hall has to stop getting in the way (which his opponent has done time and time again).