There have always been people on this site who think RoHS was a conspiracy. There are a few people who do not take the public health problems caused by lead very seriously.
Lead free solder is objectively worse as a solder for just about any metric related to longevity. So you have to weigh the risks of lead in solder against the reduced longevity of entire electronic devices from solder joint failures. Lots of BGA components have had problems related to their solder, and the usual result is that the entire device gets thrown out.
Nowadays, lead free solder is accounted for starting in the design stage. Manufacturers have had 15+ years of experience with leadfree solder and have largely worked out the issues.
Lead-acid batteries are extensively recycled. Electronics are usually just dumped in the trash, making the lead issue much more important.
Mostly those cars stay outside and the batteries tend to be expensive and highly recycled, electronics on the other hand, show up everywhere and have a poor history of recycling.
Nobody wants your old soldered electronics. That stuff is nothing but trash.
I don't buy the "just wash your hands" argument.
If you're repairing something that used leaded solder, you pretty much have to use leaded solder. That's fewer and fewer things post-RoHS, but when you have something older, you're going to use leaded or you're going to have a bad time.
With a decent iron and flux, hand soldering with lead-free solder is fine. All my new work is lead-free, but I have zero concerns having my kids work with leaded solder at the frequency and using the reasonable precautions.
And how much has gone into fuels (especially aviation fuel)?
I found an estimate of lead from e-waste (all sources of lead, not just solder) being 58,000 tons per year, roughly 100x the avgas figure.