About balancing:
Static balance assumes the weight trying to be offset is centered on the tread. Putting weight on both sides on the assembly accomplishes thsi task. Putting weight on only one side does not!
I’d estimate that static balance takes care of 60% to 70% of the vibration problem.
Dynamic balancing assumes that the weight being offset is off center, so you get a static component and a dynamic component. In theory, there should be 3 weights applied - 2 for static and 1 for dynamic - but the machine recalculates where a single weight ought to be instead of 2 weights on the side needing 2 weights.
I’d estimate that adding dynamic balancing fixes about 20% to 30% of the vibration problem.
So what about what is leftover? (and for those who did the math, it is between 0% and 20%) - Uniformity!! (think Out of Round and you will be close!) A tire can be perfectly balanced and still be Out of Round.
The video is of a Hunter GSP9700 which has the capability of measuring uniformity - which Hunter calls RoadForce. The video only covers the balancing part, but the guy does explain what RoadForce is, but only does the balancing portion of the procedure.
So it is quite possible to get a good balanced and roundish assembly by only static (bubble) balancing, but some of the time, the assembly needs to be dynamically balanced - and sometimes the assembly also needs to be measured for uniformity (RoadForce, Runout) to be a vibration free assembly.
I think ALL vehicle manufacturers specify both tire and wheel uniformity limits (in addition to imbalance limits) - and it is common for the vehicle manufacturers to require the tire suppliers to mark the high point of the tire (and there is no agreement on how to mark this, but a red dot is common!) and they require the wheel suppliers to mark the low point of the wheel (and while there is also no agreement on how to mark the low point of the wheel, the valve hole is commonly drilled in this location - but not always!). If the low point of the wheel is matched up with the high point of the tire, the assembly is rounder.
And why was static balance OK long ago? Because the vehicles were not as stiff and tight as today’s cars. Today’s car are much more sensitive to wheel end vibrations than in the past - some overly so. A certain Cadillac comes to mind where only 2 or 3 out of 100 tires manufactured were acceptable.