The American wax ring designs seem like a good candidate for crappy design post in one of these places:

!asshole_crappy_design@slrpnk.net
!crappydesign@discuss.tchncs.de

Floor-mounted toilets in the EU put their outflow out the back of the toiletbowl parallel to the floor, not below the bowl into the floor. Even if you have a bad mount that causes the toilet to wobble, it won’t leak. But if it did leak, it would be trivially detectable.

Is the US design putting cosmetics above function? Is it that they want to hide the sewer pipe entirely? I suppose if I were installing a toilet in the US, I would look for a wall-hung toilet. But another comment suggests those are rare in the US too.

pure silicone, the clear stuff that smells like vinegar

I believe the stuff that smells like vinegar is special sanitary caulk for bathrooms which comes with anti-fungal properties. Pure silicone is odorless, not for bathroom use, IIUC.