They are expensive for Europeans because they don't produce them in large numbers and they love complicating things, like the Archer extends the barrel and a double door that closes once the barrel is retracted. That system is great but can be made simpler and cheaper and can be made to go faster, too. All the PLA had to do was take the turret of the PLZ-05 and place it on a truck. This would have made for a design that shares almost all its parts with other products, introducing next to no new complexities to the supply chain and cutting development costs greatly. It would also have reduced training cost and time, and the number of the crew would have been reduced, and most importantly, it would have greatly increased the survivability due to two factors, one being the crew still inside an armoured platform protecting them from many variants of loitering munition drones and shrapnel, and the second factor being that they can leave before counter battery arrives. Then theres the element of deterrence and sales through prestige. Developing high end designs tends to attract global respect and increase sales.
There are a few other points
PCL-181 was specifically designed to fit 2 in a Y-20. It is quite possible that such a turreted design would not be able to fit this constraint.
Another thing, European militaries are facing falling recruitment numbers necessitating increased automation, PLA doesn’t have this problem. As mentioned, the increased cost/complexity doesn’t necessarily give a positive pay off.
Honestly the speed of loading is not going to be the critical factor in a shoot and scoot mission. Physically unhooking and laying a towed gun is going to take up way more time than loading five rounds with a full crew of loaders, especially since all the ammo is contained on the chassis.