Biodiesel is not meant to replace all fossil oil and will never do so. But if you were to do so (with current oil sources) it would probably leave you with little agricultural land left. You could use algal bioreactors instead those dont take up any agricultural land but are very expensive to operate. You would also still need to grow energy crops for the production of alcohol needed for the transesterfication step.

https://sci-hub.se/https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b03136 Here you go

https://sci-hub.se/https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b03136 Here you go

Biodiesel is not a good option imo the NOx emmisions are generally significantly higher. Also most of the oil thats used to create biodiesel is not sourced responsibly. The production procces also still creates toxic waste although usually less than normal diesel.

Source: i just wrote a report on this if you’re really interested. i can dig through my sources lmk

You would rather have people smoking black market sigarettes that might be even more toxic than the regular kind?I also hate big tobacco but banning sigarettes will just replace a regulated market with a unregulated one.