Balancing Trailer Tires - yes or no

Mechanics get lazy and used to skimping where possible. I found the same poor logic on my motorcycle. They claimed they didn't balance rear tires. They had zero reason except that's the way they were taught.
Makes no sense at both wheels are turning at the same speed etc.
I have had tons of issues even getting my tow vehicle wheels balanced properly, having to stop on a long trip to rebalance and fight with first shop over the botched job.