Having retired from the tire industry after 40 years, experiencing virtually every tire situation imaginable, I will give you my simple, clear view on tire blowout problems.
More tires blow out due to poor workmanship than age. That poor workmanship may not show up for a year or so after tire is in service.
'Passin' Thru''s message above says it best: 4.4 million miles without a blowout.
In fact I am very opposed to scrapping tires systematically at 6 or 7 years; certainly after they are 10 years old, but conditions vary over the USA and one age rule does not apply to all conditions and maintenance situations.
Begin with the best tire you can afford, maintain air pressure as per THE TIRE MANUFACTURER'S guide (not necessarily the RV manufacturer).
Tire manufacturer wants you to get the best service from the tires, the RV manufacturer leans toward giving you the best ride.
Carefully check tread and sidewalls at least before every RV season, and after you have hit an object in the road. Cuts or bulges is what you are mainly looking for. Of course severe weather checking should also be considered a potential problem.
My opinions based on much, much practical experience.