Why is God three persons rather than four or more? This question is about the Holy Trinity. Did the Scriptures explained that God is necessarily three persons?

[ This question doesn't challenge the Trinity if it is true but rather, the question, if answered will be for the benefit of the Trinitarian]
This question is covered in other places such as here

The bible does not anywhere in it say that god is clearly three persons. That is a human perception of what is written. There are many scriptures such as John 1;1 that obscurely support it.  There are many more scriptures that suggest that God and Jesus are separate such as 1 Corinthians 11;2. 

There is, however, no scripture that comes out and says directly Jesus, Jehovah, and the holy spirit are 1 being.