Hello,

In WordPress standards, CPT names are ‘singular’. So that’s why the role capabilities come with ‘plural’ names.

If we were to not use the plural name for role capability, then it will create a conflict. Because under the hood, both singular and plural capabilities exists. For example if you have a CPT called ‘ABC’, then both ‘edit_abc’ and ‘edit_abcs’ exist in the system. If we were to ignore the ‘s’ because ‘ABC’ itself is plural, then it will conflict between singular and plural capabilities.

Not only that I don’t think checking for an ‘s’ at the end is always going to satisfy the condition.(Ex: address)

Thanks

Syam