Doesn't seem to have been many ST tire failures this year.

Probably several things.
IMO ST tires have improved vastly from the over sized rounded wheel barrow looking tire they started from years ago.
The newest Carlisle RH trailer tire now has a conventional tire shape. Only time will tell if its a vast improvement.

I frequent several forums where trailers of all type are used. IMO it looks like about the same amount of tire issue and questions asked.

And it could be more folks are searching more input from the internet before seeking advice from a forum.