In Bhagavad Gita 3.10 & 11, Krishna says:
सहयज्ञाः प्रजाः सृष्ट्वा पुरोवाच प्रजापतिः
अनेन प्रसविष्यध्वमेष वोऽस्त्विष्टकामधुक्देवान्भावयतानेन ते देवा भावयन्तु वः
परस्परं भावयन्तः श्रेयः परमवाप्स्यथsahayajñāḥ prajāḥ sṛṣṭvā purovāca prajāpatiḥ
anena prasaviṣyadhvameṣa vo'stviṣṭakāmadhukdevānbhāvayatānena te devā bhāvayantu vaḥ
parasparaṃ bhāvayantaḥ śreyaḥ paramavāpsyatha
By yagna (sacrifice), devas are pleased, and in turn they please humans.
In Kali Yuga, almost nobody does yagnas, or their frequency is negligible. Even the orthodox brahmanas who attempt them have to deal with lot of impurities of dravya, mantra, bhava. Nitya Agnihotra itself is gone from most households.
So, how do Devas get the ghee + rice havis ? Without that, how can we expect them to give us rains, food, aushadhi etc. ?