The videos, the security cameras footage, alongside numerous first hand accounts paint a very clear, minute by minute picture, which I'm not sure you bothered to look into.

Hamas raided numerous towns near Gaza where they murdered people and children in their homes. This is where most people died. This and the music festival where people literally came to dance peacefully.

Under no circumstances did IDF kill 1200 Israeli civilians on October 7th, or "a substantial" part. This is disinformation and Hamas propaganda, and any source even implying this is lying to your face.