I have been on both sides on this. I was trapped in a Buddhist group. Considering that the teachings where flawed or wrong would basically mean that I would lose out on that community. Believe me, the sense of belonging can be euphoric in a religion.
Of course, changing your view in isolation is quite easy. It becomes harder when a big part of your life requires you to believe.
Also, when I was younger my need to “be right “ was quite strong. I had severe self confidence issues, so “being right” was the one thing I latched on to. Admitting being wrong gets really hard once your self confidence is that shaky.