Yes siddhis are illusionary just like senses and is a temptation or a bait of God to raise a man to higher realm for no Siddhi is possible without sadhna, yoga, self-restrain.
One day, Sri Ramakrishna took Narendra to the Panchavati and told him,
'Look, I possess the eight occult powers. But I decided long ago that
I would never use them and I find no need for them. But you will have
to preach religion and do many other things. I have decided to give
those powers to you. Please accept them.' Narendra asked in reply,
'Will they help me realize God?' When Sri Ramakrishna explained that
they might help to some extent in preaching religion but would not
help him attain God-realization, Narendra declined those powers.
The desire to possess siddhis is same as desire of possessing something by the false non-luminous ego and mind of Prakriti which is inert in reality. Everyone desires to be Omnipotent, immortal and beautiful, the desire comes from Purusha/soul.
Patanjali Yoga Sutras
These are obstacles to Samadhi; but they are powers in the worldly state.
By giving up even these powers comes the destruction of the very seed of evil, which leads to Kaivalya.
The states of the mind are always known, because the lord of the mind, the Purusha, is unchangeable.
18. The mind is not self-luminous, being an object.
The mind, though variegated by innumerable desires, acts for another (the Purusha), because it acts in combination.
For the discriminating, the perception of the mind as Atman ceases.
Then, bent on discriminating, the mind attains the previous state of Kaivalya (isolation).