I feel like this is one of the cases of serendipity. Sure, decimal points might be partially the result of Bianchini’s creative mind, but also from the fact that he was well-travelled, in a country that valued contact across multiple civilisations, bridging together Western Europe, the Byzantine realm, and the Muslim Mediterranean.

The later is specially relevant here, as decimal fractions were used in the Levant since at least the 10th century; I think that they used a bar instead of a point, but even today you see some variation (e.g. a decimal comma is fairly common among Romance speakers).