is there still not sure if XRP is coin crypto currency?
I am still sure it is not a cryptocurrency.
I have a bit of a problem with these two contradictions in your post.
If it is centralized then trust in it is centralized, therefor you need to trust some group of people.
And if doesn't use a blockchain and it isn't decentralized, it really has no place to be called a cryptocurrency.
A cryptocurrency needs to be decentralized and open source in my opinion. Anything else is simply not a cryptocurrency.
There is not a lot of difference between Ripple and online banking. Online banking uses cryptography as well and has a certain security protocol.
It just isn't a cryptocurrency, it is a digital currency.
If something is more like a conventional banking system than Bitcoin, then you can make your own conclusion on what it should be called.