From Itivuttaka 4.8: This was said by the Blessed One, said by the Arahant, so I have heard: “Monks, brahmans & householders are very helpful to you, as they provide you with the requisites of robes, alms food, lodgings, & medical requisites for the sick. And you, monks, are very helpful to brahmans & householders, as you teach them the Dhamma admirable in the beginning, admirable in the middle, admirable in the end; as you expound the holy life both in letter & meaning, entirely complete, surpassingly pure. In this way the holy life is lived in mutual dependence, for the purpose of crossing over the flood, for making a right end to stress.”
Alms-giving is a two-way custom.
It is also about Dharma-giving.
It is not just about monastics being given respect,
but about monastics respecting laity too,
of no one taking the other for granted.
The Buddha was ingenious in ensuring that alms must be gathered daily,
so that monastics don’t stray too far from society.
while the laity give material food generously that is humbly accepted,
the monastics give spiritual food generously that is gratefully accepted.
a win-win situation based on interdependent merit-making, Dharma learning and sharing.
When monastics start to become self-sustained in terms of money,
it has advantages of convenience for them,
but is also the possible beginning of pride and corruption.
When the laity becomes farther distanced from,
the direct giving of Dharma in person becomes less too.