The P232 wasn't designed with concealed carry in mind. It was designed as a service sidearm with law enforcement in mind. The gun was widely used for that in Europe and parts of Asia. Very popular in Japan for years as a service sidearm.
It's true the current Hogue grips are thicker than the original style grips.
The gun is overall, meaning in all dimensions, larger than the Walther PPK (which was built with concealed carry in mind) or the PP. It's larger than the old Colt M1903.
Aftermarket grips will help this though. Thinner grips can be found.
There is only one answer to the existential question "Why is it this way?" It's that way cuz that's how they built it. It's how they wanted it. If you don't like it get thinner aftermarket grips.
The 232 is a very good gun nowdays for the same size we can get a 9mm. Not as comfortable for all to shoot though.