What broke the franchise for me
I love the first film like many. I do still to this day have a lot of fun with the second one. After that the franchise is pretty much all garbage for all I care. I do appreciate them in a guilty pleasure kind of way but it is definitely bad.
But the biggest problem of the sequels IMO is the steer away from the psychological horror to a more gruesome, imediate, graphic and quick response horror.
What works in the first movie is the slow burn. The games in the sequels last a couple of minutes while most of the games in the first one last for hours or even days. It's that kind of horror that I'm mostly interested in, especially because then you're able to put yourself in the position of the victim and ask yourself what would you do.