It took a lot of effort for us here to 'survive' here in samsara, where the weak gets pushed around and gets eaten by the strong. Law of the jungle (but in reality, law of samsara) and if we 'fall', we'll simply get trampled by more powerful beings and this is a cycle, so in order to make it to be born as humans we would have to put a lot of effort in already. It would be a waste of efforts if we do not use just a little more effort just to achieve Bodhicitta or put Dharma practice into action. So yes, endeavor is very important for any practitioner who wants to make it.