Now.. and I am speaking just from the perspective of trying to achieve specific goals ( and accepting a level of pain for what those goals can demand ), if there was ever a possibility that US may ban/fully sanction bitcoin use, this actually might be it.
They don’t need to ban bitcoin use - they just declare paying “insurance” or “tolls” to the Iranian government to be a sanctions violation, irrespective of the means of payment. Then this becomes a complete non-starter for any US company, and any non-US company in nations where the US has significant influence (i.e. most of the West)