They are basically the same.
Firmer balls generate more swing speed. A ball with more ball speed goes farther than a ball with lower ball speed. So, for most golfers who generate enough spin, the firmer ball goes farther.
For some golfers who generate less spin than they need, a softer ball can help them generate more spin to make up a little distance.
Think about this: the “distance” balls of the 90s? The Pinnacles and Top-Flites? They weren’t nicknamed “rock-flites” for nothing.
A firmer ball will go farther for the majority of golfers, even if they have a lower swing speed. Two final points:
We’re talking about literally a yard or two or three. A ball is not going to add ten yards Other things - like the short game control - matter more.
You don’t swing your 5I at the same speed you swing your driver, so it’s not like a Pro V1 or some other firmer ball doesn’t perform once you get to slower swing speeds or ball speeds. This is more true now than ever.
Cases are actually dropping in my area. So much so that they had a Covid floor changed back to normal patient care last week. That's a significant improvement.
Maybe not total positive cases but in house patient numbers have dropped. I'll word it that way
So, what happens when the impact parameters are different, like, 115mph swing speed at impact and 85mph swing speed at impact. Which ball would be better to use? Terms like fly further and stay in the air longer seem to be the same outcome, just worded differently.