What you’re saying makes no sense. You’re rejecting evidence that contradict your conspiracy theory and instead make up a totally unsubstantiated “it’s just for appearances” fantasy.
Just to name one example as to why what you’re saying is absurd: Roof-knocking, which they are still doing, costs just as much as an actual air strike and is militarily disadvantageous, since it allows militants to get away with the civilians warnings like these protect. Israel is willing to increase the cost of air strikes and reduce their effectiveness at the same time, just to save lives. Based on how many self-proclaimed pro-Palestinians I’ve talked to, most are not even aware of what roof-knocking is, so clearly, if this was a PR campaign, it’s been a complete failure.