That is far from obvious. A command structure scattered around a huge country should be able to outlast U.S. willingness to throw bodies into a shredder.
Harder, sure, but it's unlikely Iran could stop a US invasion since a ground invasion would almost certainly only happen with the US having complete air supremacy.
> Russia has unimaginable losses and they still haven’t reached their strategic goal.
Russia does not have control of the airspace in Ukraine, the US was flying even non-stealth aircraft over Iran for most of the war with negligible losses for those aircraft.
The US with combined arms warfare capabilities and air supremacy is very difficult to defend against for a country like Iran in the event of a ground invasion.
The Americans learnt from that and went to Iraq claiming to have hearts and minds on their side - but quickly discovered that, in fact, they did not (and still do not).
The Americans need to take stock of their own actions in this conflict - they put Trump in the white house, they allowed him to be influenced by other governments, they gave him the power to get involved in the conflict.