The prostration is not important in terms of respect. Allah wanted to test His creation and wanted them to accept the creation of man. Allah showed Adam (AS) that while angels are the superior creation but their superiority comes from the fact that they obeyed Allah’s command whereas Iblees despite being a jinn and superior creation to man, became worse than all creation because he disobeyed Allah’s command. A lesson to Adam (AS) (and to us) that why humility and obeying Allah is important and why arrogance leads to rebellion to Allah and downfall of creation.
Generally angels respect all obedient creation of Allah (see Qur’an 41:31) but there is no respect for the rebellious among creation. (see Qur’an 2:161)