Hi,
I think it's not an easy question to answer and everyone might have a different opinion.
The political issue between US and Iran's government during the past few decades is nothing new but it escalated during the past few years. To obtain a visa, work permit, permanent residency,... in the USA or any other country there is a need for background check but if you are Iranian based on united state government website Iranian police certificates are unreliable since they can not verify them so you do not need to provide a police certificate from Iran. It only make sense that the background check for Iranian would be longer and this is what we even see in this group for Iranian nationals or dual citizens. Having a second citizenship means that they can check you through a trusted country and might make the process faster/easier.
Also, some passports doesn't allow you to travel visa-free to many countries, if you have a work-related travel, seminars, workshops, conferences,... coming up while you hold a green card you need to get a visa every single time meaning you need to plan 3-4 months ahead, getting appointment, filling forms,...
Consider the fact that you can apply for U.S citizenship only after 5 years (unless your spouse is American) and there is another background check for citizenship that might take longer than others...(if another pandemic doesn't happen and make the wait time longer), see what is best for you and make an informed decision.
I do not have much of information about other nationalities, their passport strength and the diplomatic relationship with the USA, so I can not speak for others.