Not right to design same UI for both Android and iOS. But what is the number of users having both Android AND iOS?

Discussions for having same UI for both Android and iOS has been ongoing since ages and the majority of people think that design for platform is better than using same UI across different platform (See here, here, and here. Correct me if my understand is wrong or if the current trend has changed).

However the idea that different platforms having different guidelines and user behaviours doesn't convince the organization that I am working in, as having a consistent UI seems important for them.

Is there some statistics to prove that majority of the people only have devices from one platform (and it might take a huge majority number to convince the organization)
If this statistic is not 'convincing', is there other numbers to prove that users do not like UI that seems to be taken from other platforms?

Alternatively, is there other supporting evidence that is not subjective to show that designing for the platform is the way to go?