yemen was occupied by joint forces of saudi arabia and UAE, before the iran war the UAE took their soldiers from the country and the gap wasn’t filled, which made controlling the houthis a very much different and difficult issue. furthermore, iran has been steadily destroying the empire’s military bases and support gear which makes everything more difficult. yemen has a history of struggle, so that also plays a big role.

ultimately, it’s not necessarily money, or advanced tech that wins wars, but rather knowing how to use what you have to your advantage. history is filled with smaller enemies beating giants. the us hasn’t won a war in decades.