You're right, the level of bombing the US can and would carry out is far lighter now.Iran in 2026 is not comparable to Vietnam in 1970
But for other examples: it failed in the Chechen wars, Syria, Gaza, Yugoslavia, Russians invasions of Ukraine, Afghanistan and Gulf War 1. It's easy to list conflicts where bombing failed to achieve regime change or people to crumble and surrender, because it's pretty much every war.
The bombing didn't topple any regimes, infantry invasion was needed to do that, and they mostly failed too.
