You are correct!
I worked at a tire manufacturing plant for many years, balancing is a good thing for your trailer, car, truck, etc.
It definitely can't hurt anything to have them vibration free. No reason not to balance any tire that sees speeds over 30 or so.
Somewhat related, this week I got reminded of how important road force balancing can be. It was a set of refurbished wheels and more winter friendly tires for the GT AWD.
Three of the four were rejected by the Hunter GSP 9700 for having excessive road force numbers, and not only by a little bit. After measuring rim run-out (a simple procedure) the machine shows exactly how much to turn the tire on the wheel to make two discrepancies cancel each other.
It also shows what improvement to expect, and for the worst one it would go down from .052 to .034. That's still quite high, but obviously better. After doing the match balance it came out to .006! Yes, the worst one became the best of the four.
A regular spin balancer would've simply asked for small amounts of weight (to get them right required a fair bit more) and the machine would've declared them balanced. Not true in real life. You can balance out a piece of 2x4 attached to the tread, but that won't make it go down the road nicely.
Also, more often than not, the tire and wheel combo with the most weights is actually the smoothest running one.