Just the normalizaton of this practice is good ngl.

If a billionaire donates 2.5% of his money out of their goodwill they get bunch of supporters and tax breaks and people forget allegation on how they raped someone and so on.

Meanwhile even kings, who could do whatever the fuck at the time, were expected donate at least 2.5% in 600s.

More progressive taxing can not only be justified in hindsight of modern capitalism, but can become commonplace and expected too.

Also unrelated but not a single king quit being royalty because they had to donate 2.5% of their ownings so that "taxing the billionaires would unmotivate people to start business" was absolute bs for a good 1400 years lmao.

Under an Islamic rule, the Muslim is forced to do this donation. And Muslim billionaires are not all of a sudden all pious because they have this label. Islamic law doesn't eliminate the need to study politics and sociology you know. Many Muslim scholars, claimed that it could in fact end the poverty in the Islamic world if really all obliged muslims paid their zakat (which is a requirement for Islam, not like a side quest, and should be enforced legally), among them Dr. Abd Al-Rahman bin Hamood Al-Sumait a humanitarian. This might appeal to you?: https://www.theguardian.com/global-development-professionals-network/2017/jun/22/zakat-requires-muslims-to-donate-25-of-their-wealth-could-this-end-poverty