Notice how the trapway drops to the floor level, and that sharply turns toward the drain, and then a hole is cut on the bottom of the toilet for waste to drop down. This is where I find most of the clogs.
The bends are too tight.
It may be rated at 500 grams, but that is with test media of 3/4" by 4" plastic wrapped paste.
In homes, you may not be flushing items like that.
I replace quite a few of these for the leaking flush valve seal, and to replace with a better performing product.
Kids can do a number on these.