Mitzvos Hateluyos Baaretz (Teruma, Maaser, Shmitta, Orla, etc..) is one of the reasons that people are more machmir when it comes to hechsherim in Eretz yisroel. For instance, the OU infamously relied on the heter mechira for shemitta (although they don't anymore). So even if their standards are comparable to the US, many people opt not to rely on them due to that reason.