Airports are large. As in "huge". This is not obvious from airplane traffic, as airplanes are also fast, so they cover the distances at a proportionate speed. Check out any emergency landing videos where firefighters are visible: the trucks seem tiny and slow, even at top speed (which could be ~200 kph). Speculation from reports: firefighters were a) expecting them at a different rwy, b) chasing the plane as it touched down, but no video long enough to actually see them arrive.
Alright, let's not overdo this.
I live in Frankfurt and I know what a big airport is. I also know that fire trucks are not THAT small...This was an emergency landing. The trucks should have been all over this plane the moment it touched down. Just as you can see it on many videos of even less dangerous situations. However there is not a single fire truck to see here: https://www.youtube.com/watch?v=WmvcoAPLeuA nowhere. Even when people were already away from it. Also here: https://www.youtube.com/watch?v=GX_tMKmUjbg you see people starting to get out of the plane. Nothing. There is some kind of vehicle coming over at the end but it's not a fire truck.
In this video (around 2Mins) https://www.liveleak.com/view?t=k5Lw7_1557086404 you see finally water from obviously a single fire truck being sprayed on the plane but there must have passed a very long time since the vehicle from the other video is standing on the right site and people are gathered around it.
So please. Don't tell me there isn't a massive fuckup here.
The fire trucks do not know where the plane will stop on the runway. A plane coming in to land will be going well over 100 mph. The fire trucks cannot be on the runway ahead of the plane (lest they be taken out by the plane and make the crash worse with the side benefit of now having more victims and less first responders).
It is physically impossible for the firetrucks to be at the plane the moment it stops.
That is one thing I did not say - just that I have not seen any footage longer than ~1 min. I surely would have expected more than a single fire truck responding after a longer period.