Islam, strictly prohibits the withholding of wealth by the wealthy.
A time will come when everybody will be wealthy that the Muslim can no longer fulfill his duty to give zakat from his wealth because no one will be in need of any wealth.
Everyone on Earth is wealthy.
Narrated Abu Hurairah
Allah’s Apostle Said, “Whoever is made wealthy by Allah and does not pay the Zakat of his wealth, then on the Day of Ressurection, his wealth will be made like a bald-headed poisonous snake with two black spots over the eyes. The snake will encircle his head and bite his cheeks and say, “I am your wealth, I am your treasure.” Then the Prophet recited the holy verse. — ‘Let not those who withhold… ‘(to the end of the verse) 3.180
Vol II, Book 24, No. 486