1. This is not just about police attacks against journalists across the U.S. in general, this is about attacks since a specific date. The date matters because it is recent, it delineates a specific span of time (a mere five days), which helps the reader place it into context. This is about the protests that have occurred since the murder of George Floyd.
2. This is not just about some rare occurrence of police attacks against journalists since a specific date, this is about how this happened many, many times, and as the article notes, in the majority of the cases the journalists were clearly identifiable as press. This places it in context again: this is not a one-off incident, but something that has happened with startling frequency.
With the original title, it is easy to identify a through-line from the start of protests against the murder of George Floyd to a startling factual statement: on average, each day since then, police have attacked journalists over 20 times a day. Or to put it another way, police have attacked a journalist almost once an hour since the protests have begun.
That context is vital to the discussion, if as you say the headline has such an enormous impact on the conversation that follows. If, as I see in your recent edit, the distribution function is changed because the headline specifically calls out that high rate of attacks on journalists in a small window of time, then I think it moves that function for the better.
(Sorry for editing my comment on the fly like that - yours is long enough that I imagine I changed the carpet under you several times while you were writing. It's the most convenient way for me to craft responses, so I do it all the time, even though there are downsides.)