Scoff if you like but here is my opinion using no classified information whatsoever and relying only on what has already been published (albeit in a discreet manner) to piece together what I conclude happened. I worked in that business for a long time but nothing in intelligence is perfect and I could certainly be wrong.
Bibi and Mossad were told by the US and by Egypt that Hamas was about to attack. That has been published. It is absurd to think that we knew more about Hamas's plans than the Jews. They logically already knew. We were covering our bases as a matter of redundancy. That's how it's done.
Israel was in a catch22. If they moved in before the Hamas attack and busted up the plan, that does not solve the problem. They would not have world wide opinion/support in their favor to go further and deal a fatal blow to Hamas. I believe they assessed that over time, many more Israelis would die than died on Oct. 7th because Hamas was getting very strong, large, well organized, entrenched and armed. Plus, the leadership of Hamas is ultra hardline, unreasonable zealots and there is therefore no peace with them. They simply will not have it. They are dedicated to destroying the Jews or die trying; this even though the Quran refers to the Jews as the children of Israel. What it means is, Hamas is nothing but a hate group. They have no scriptural/religious basis.
So, Bibi had a terrible decision to make and it's my opinion that he made the decision on the side of longer term security rather than just stopping the initial raid. Whether they knew the details of the raid or its magnitude/size is not clear at this point. I tend to conclude they didn't think it would be as bad as it was.
You seem to want to blame Bibi. I say if I put myself in the same position, God help me, I would do what I think Bibi did. I think it's what he had to do.