The industrialized world/first world tends to have stricter codes, regulations, and laws based on crowd-crush disasters in the 19th/early 20th century, such as the one involving the Iroquois Theater that killed 602 people in 1903.
We do get them but they tend to be combined with a simultaneous other disaster, like a fire (Iroquois Theater, for example). The most recent to hit triple digits in the US was the The Station fire in Rhode Island in 2003, with 100 deaths. It wasn’t that long ago.
Even in places that are prone to such disasters, though - Mecca during the haj being one example - death rates have been dropping over the past century. My guess is that the concept of “crowd control” and measures to discourage/mitigate such situations have been disseminated world-wide. They aren’t always followed, of course, but such knowledge and practice probably has helped considerably.
Perhaps you should contact Wikipedia and suggest the addition.
Even if all safety procedures are scrupulously followed any time you have a large, dense crowd of human beings there is a risk of such an event occurring. From what I’ve managed to find out on line, attendance at the festival this year is about 1/3 of a normal year. Given that annual Lag Bomer parties have been held in that location since the 2nd Century AD without such tragedies being a common feature of them I have to conclude that there is an element of bad luck at work here.
That said, of course the event should be investigated and if changes can be made to make such a rare event even more rare and unlikely that would be a worthwhile thing to do.