C# Exception handling and code maintenance [on hold]

I have a validator class in this, I will be validating(Empty or Not and duplicate) the data type values like string, int, GUID, List etc.

For this, I am throwing Argument null exception in case of value null or empty and custom exceptions for UserNotFound, duplicate, a record not found etc.

Previously I used to throw the exception directly like below,

 **throw new ArgumentNullException(paramName);**

But, I feel it be huge change If the custom exception class name changes or any modifications related to that.

Because I will be using those custom and predefined exceptions in 30+ applications.

Now I restructured it in below manner,

1. A class which throws all custom exceptions,

2. Usage of those custom exceptions here,

Can anyone confirm whether it is okay or not?

If it is okay, what type of benefits I will get from this I was unable to understand.

Let us know your thoughts on this.