The damage caused by leaded gas (even what little remains via avgas) is probably much, much higher than that caused by electronic solder.
Lets consider the 3 following ways that lead can enter the supply of materials that go into humans.
1. Leaded gas was a big big issue because the lead is now a particulate in the air, it will be breathed in or will settle as dust into either a water supply or onto soil which then gets rained on and drains into a water supply.
2. Lead solder on pipes, while not a particulate immediately, it will sometimes corrode into the water in the pipe because lead/copper touching and being dissimilar metals (always have to be very careful with dissimilar metals when in a wet environment)
3. Lead solder on electronics, will probably end up in the dump where they will there be rained on and the solder may enter the water supply that way. Note that equipment that is supposed to last a long time or will not be disposed of into a dump are usually exempt from the lead ban. In particular military, medical, and aerospace equipment is usually exempt.
Considering that the removal of lead from gas and paint caused blood lead levels to go from 16 g/dL in 1976 to only 3 g/dL in 1991, while lead in electronics was only regulated in 1993, the removal of lead from avgas is a much bigger issue than the removal of lead from solder.