Point of correction, we Muslims don’t pray because of worldly needs alone. And asking what a billionaire is still praying for shows a big misunderstanding of what prayer means in Islam. Salah is about submission, gratitude, and acknowledging our status as servants of the Almighty.
Wealth cannot not buy you a pass out of your obligations to the Creator. A rich man needs forgiveness, peace of mind, good health, and a favorable standing in the hereafter just like anyone else.
On that prayer mat, your net worth is zero. In fact, some of the ordinary persons behind him, might hold a higher status in the sight of the Almighty.
So, Dangote is sitting there as a servant of Allah fulfilling his ultimate purpose of why he is on earth in the first place.
Allah knows best.