I'm a train driver. I never even try to brake when I see someone crossing the track (unless of course if I could immediately see that I'm going to hit someone or if it's clearly a suicide, but luckily never experienced that). The difference between braking or not at these speeds is negligible, and at full speed you're talking about braking distances close to a kilometer. But damn, you'll be hearing some swear words in my cabin. I've often thought I should put a dash cam in front of me to show these idiots what we see from our point of view and then ask them what they think of it themselves.

Also, to everyone who may do this and think: but when I hear the train, I'll just get off the tracks. When you hear the train, it's too late, you don't hear trains coming until they're almost next to you. And if you then say that you can see it's far away: it's coming at you much faster than you think (people are very bad at estimating the speed of big things), and you also need more time to cross the tracks than you think. In the time you need to get to the other side, the train will have done hundreds of meters already, and that's if you don't slip.

There's also a reason why you see several people apparently not doing anything when you see a group working on the tracks. It's not because railway workers are lazy by definition, but there are several actively looking for trains all the time to get the tracks clear in time, and there will usually be someone hundreds of meters away in both directions who's in direct contact to someone where the workers are to get them away in time (or if they can't get confirmation in time that the track is clear, to signal the driver to make an emergency stop). We as drivers have special procedures to block the traffic if we ever need to be in the adjacent track (Infrabel loves it when we have to make use of that...). We don't mess around with these things, we know what we're dealing with.