To produce just 25% of aviation fuel from vegetable oil in 2050 at average oil seed yields globally would require at least 1/3 of global cropland and more likely all. Europe recognized problem, so crop-based biofuels do not count toward its sustainable targets. U.S. should too.
Biofuels require working land to produce. Powering planes with biofuels requires ALOT of land. There is a finite amount of land. If we expand demand on working land we risk food insecurity & conversion of remaining ecosystems w/loss of carbon & biodiversity. SAF isn't sustainable