It had a long run for this day and age. Most movies are in and out of the theater in a month or less, even the blockbusters.
It was a pretty good film. My son liked it and I didn’t fall asleep so it was better than lots of the crap that they put out.
I am not surprised that it made a lot of money. That was probably a foregone conclusion no matter how good or bad it was.
It seems like only a few years ago that big hit movies would play for a very long time before going to pay per view.