Trailer size and available reserve definately has something to do with it. My made in 2005 22ft trailer came with ST205/75R14 Highway master (Greenball) tires made in early 2005. I bought a wheel and carlisle tire as a spare. My trailer is 5200lbs loaded with about 700 on the tongue. So just say 4500lbs on 4 tires is only 1250 per tire rated for 1760. About 71% capacity. Speed limit in CA is 55 for towing, so I never get over 65. I always keep at max pressure.
The first year I lost one tire due to a hazard puncturing the sidewall but it didn't blow out. Replaced with another similar Greenball tire.
Last year I moved one of the the Highway masters to the spare position because of a large sidewall crack.
Last trip out half the tread came off the carlisle but it stayed inflated. No damage to the TT. I half suspect this was due to the trailer leaning heavily on a chock due to the slope of my campsite. The Highway master with the large crack held the last 10 miles home.
So I got 9 years of ouf my China ST tires. They are to the point the rubber is starting to dry rot, and they are getting replaced today before we go on our next trip. At 14" I don't have a lot of options, but at only 70% capacity on the existing tires, there is no need for me to try to go 15" or 16". My limited funds also do not allow me to buy expensive tires, that still recieve complaints.
You can find plenty of complaints about any particular tire if you look, because when someone is unhappy about something they are very vocal vs being satisfied. You hear more about China tires because they are on a lot more trailer. For every one person with trouble with these tires, there are many many other satisfied people that you don't hear from.