It's hard to see how the US benefits because the US is geographically very far away from this region but I don't think it was an expensive war: short duration, mostly just an air campaign. IMO Trump did this to send a message to the world.

Gulf countries and Israel should feel much better though, despite the losses, knowing that Iran's capacity is now limited to terrorist-like harassment. This is not the end however as the US, Israel and hopefully other countries should continue to monitor Iran closely.