Blowing smoke ! Nothing wrong with good quality tires as long as you are not exceeding the load capacity and are keeping them properly inflated.
The smaller the wheel and tire, the faster it spins. The faster it spins, the more important good lubrication is. Every time you fuel up, check the temp of the bearing/hub. If you are spitting lube or you can not put your hand on it for more than a second, it is time to re-lube/replace the bearing.
An extra 2 sets of bearings are cheap insurance. Tools/grease to do the job are cheap insurance. A second (even unmounted) spare is also cheap insurance.
eTrailer does not sell "junk". Call them.