Perumal performs many activities on behalf of Devas like carrying bridal gift for Meenakshi, appearing at the tip of Paramasiva’s bow for Tripura samharam; he also appears as Upendran for Indran’s army. This is his way of gracing the Devas.
Emperuman is awaiting to grace us directly. We can acquire all auspiciousness if we directly worship Perumal.
As all demigods are under the control of Emperuman, we will not beget their wrath if we do not worship them and worship only Perumal.
It is appropriate that we do not worship other gods as it is akin to being a chaste wife who is faithful to her wedded husband. Emperuman is our only husband and after being wedded to Him, it is our duty to worship Him alone.
As it is not a custom, Sri Vaishnavas do not celebrate Varalakshmi Vratam.