In SF, the jail will only accept bail from registered bail bondsmen. They will not accept bail money from the arrestee, friends of the arrestee, or family. The average rate for a bail bondsman is 10%. A common practice that a vindictive police force will use is tacking on charges that they know will not stick in order to push the bail higher (eg Felony Conspiracy to Commit a Crime can be tacked on to any crime involving more than one person regardless of its nature and will set bail at $18k minimum). My neighbor is a criminal defense attorney and I asked her about this; she said that it is common knowledge that the SF DA, police, and bondsmen are all scratching each others' backs.
An initial court date can take a few days to a week of waiting in jail, which means missing work. An innocent person -- or a person guilty of a victim-less crime -- of little means will likely lose their job as the result of one arrest if they cannot afford bail.
The other practice that is commonplace in SF and California is confiscating a phone as evidence even if there is no reason to believe the phone will have evidence. Even if a person is wrongfully arrested and the charges are dismissed, property return is only done if the District Attorney elects to cooperate. If the DA does not voluntarily request the police return your property, then you need to file a motion to obtain a hearing. The going rate is $500+ to have an attorney do this. Most people simply do not get their phones back because the time and monetary cost are too high. If you are living in an expensive city on a tight budget, this is a significant loss.