The only time I’ve had anything close to a clog, it was as a young teenager and because of excessive quantities of toilet paper. And the solution was just to add more water into the bowl, which increased the water pressure in the s-trap and pushed the blockage through.

Really it should be impossible to clog a toilet with poops alone.

And if you find yourself excreting an unusual amount in one sitting, or need to use an unusual quantity of paper, just do an intermediate flush.

In the US, they're for sale everywhere. And I must acknowledge their ingenuity when it comes to toilet plunger design: American plungers have an additional "lip" at the bottom of the rubber thingy that fits into their toilets quite nicely and seals them up better than the usual plungers in Europe would do, which don't have that extra rubber lip.

Apparently the extraordinary demand for plungers resulted in better plungers, not in someone asking "why the heck are we so reliant on plungers?" and possibly making better toilets ;-)