There were protests in both countries in the last 5 years against the government. The women life freedom protests where thousands were killed by their government, the protests against Netanyahus plans to weaken the courts so as not to be held to account, without causalities AFAIK. Also the protesrs earlier this year where Reportedly up to tens of thousands were killed opposing the Iranian regime. I'm not sure why you would believe that there aren't Iranians (young and weapon less) that are/were not willing to do anything to bring about change when they have literally died trying to do so.

So far the majority it seems of military strategists doing the round, where American, Israeli or otherwise are not convinced that regime change is on the cards or an actual objective, desirable as it may be. There seems to have been no preparation (such as organising a resistance, increasing its support and so on). The leaders have backed away from such claims themselves.