Don't confuse ruthlessness for competence. Israel does a lot of things because it knows it can get away with them. Israel is also known for spreading blatant disinformation. Occam's Razor suggests they were unprepared for the Oct 7 attack because they simply didn't see it coming even if they knew Hamas was up to something.
When having terrorist organisations shoot bottle rockets at you or have their members blow themselves up is a common occurrence and your tolerance of collateral damage in your military counter-attacks is so high that you've continuously killed an order of magnitude more people in your counter-attacks every year while maintaining a much higher ratio of civilians casualties per military target, you don't actually need good intel because your mode of response defaults to "just kill 10x as many of them as they killed of us".
When having terrorist organisations shoot bottle rockets at you or have their members blow themselves up is a common occurrence and your tolerance of collateral damage in your military counter-attacks is so high that you've continuously killed an order of magnitude more people in your counter-attacks every year while maintaining a much higher ratio of civilians casualties per military target, you don't actually need good intel because your mode of response defaults to "just kill 10x as many of them as they killed of us".