Could be anywhere between a minimum of 10 minutes (maybe 20 with bags) and 90+ minutes.
10:30am is right at the start of a period with a large number of arrivals into SFO with around a dozen flights due within just over an hour (split across the two immigration halls). Depending on where they land within that list will dictate how long the immigration line is in front of them is.
Most ESTA visitors are being pushed to the kiosks now days which helps, but if there happens to be an Asian flight or two in front of you then there can still be a lot of non-ESTA people.