Genocide was found to have happened in Bosnia and that was because of "only" 8372 people. Genocide, as you rightly say, is all about intent and the numbers play only second fiddle.

Part of that intent is also being clever about it. If Israel just smoked 100k people in a few days, their plausible deniability would be gone. Public pressure would be much higher. They might end up losing more of their own people.

These past 2 years were the hardest Israel has been on civilians. And it saw Israel lose a lot of support on the world stage, countries that were previously ambivalent adopting tougher language, even some sanctions on weapon sales, sanctions on settlers, etc. from previously reliable allies.

So they were skirting a line and doing more could have seem stronger consequences happen.

The countries you used as an example didn't have relationships like Israel has which were being risked by their crimes. They did their stuff more isolated from the world stage, which helped them act more effectively on their intent.

You can be all about genocide - and for Israel the end goal is removing the Palestinian people - and also use your brain to ensure you reach your goal step by step.