It's certainly has multiple for me. I was skeptic as a teen, the OCD wrecked my will to believe, and destroyed the often used argument that god ''guides'' you personally for me.
I then began to form the argument by humans being so sinful by biological nature it seems strange God created us and proceeds to be disappointed.
Aside from that, I gradually learnt more about the debate, and the more I thought about it, the weaker most theistic arguments seemed, and the stronger the atheistic ones. The argument of senseless suffering also was a big one for me. Plus I learned more stuff that made the bible less and less true for me.
And then it all combined, the natural sinfulness with doubt of the bible, and all the surrounding arguments, my personal experience being negative.. It's all linked, and I only dared to deconvert when I felt sure enough.
So yeah, multiple arguments, and I need to have multiple to not get thrown back into doubt limbo, which I have grown to hate by now.