they got air support against ISIS, you remember that correctly. But regime change war was against Assad, who the YPG never fought against. There was also a whole news cycle about how they were abandoned by Trump so Turkey could come in. They were never given any (heavy) weapons (like the mujahideen got for example) and the U.S. dismantled all bases when pulling out. They were treated terribly compared to all the 'moderate rebels' yet they were more successful 'allies'