Israel and the USA attacked Iran jointly; and the obligation for ensuring Israel ceases fire was undertaken by the US. If the US were to adopt your position, then there never was any cease fire, because the basic tenant of the MOU is everyone ceasing fire, including Israel.
Good for them. However, the USA signed a deal with Iran that is only valid if Israel stops attacking Lebanon, otherwise the USA is in violation of that deal. It's the USA's problem how to enforce this.
The USA controls Israel's purse strings btw and if it just stopped sending it money the war would be over in a few months - and there probably wouldn't be an Israel any more, so Netanyahu would do well to prevent the USA from choosing this option, by following any terms imposed by the USA, like to stop attacking Lebanon.