What does it mean that fortune tellers sincerely worship fake buddhas?

Humble opinion: Buddhism believes that there is no difference between heart, Buddha and sentient beings, so sincere worship is the real worship of Buddha. The fake Buddha here should refer to the Buddha statue or portrait. Of course, we can't deny the existence of the Buddha statue, because it can inspire people's sincere hearts. Therefore, sincerity is the most important thing. If you can keep a true and pure heart when you walk, live, sit and lie down, you will always worship Buddha and have boundless merits.

How to keep a true and pure sincerity when walking, living, sitting and lying down? The easiest way is to recite Buddha. You can recite "There is no (mó) A (ā) Mi (mí) Tuo (tuó) Buddha in the south" every day. You can recite aloud or meditate, and you will be blessed by Buddha and Bodhisattva in this life.