Product review (1 stars): Same garbage as the original part.  Grease doesn't help.
This would have been several hundred dollars to have a repairman fix it.  Most of the youtube videos about how to fix it suggested taking the whole dang dryer apart -- instrument panel, top, front, drum -- to get to it.  I accessed it through the 4" vent hole in the back by removing the one screw that holds the vent hose in.  It's not easy to install this part through that hole, but it can be done.  Before installing it, I greased the bearing surface with some white lithium grease.  Hopefully that gets some more life out of it.
Update:  This replacement part lasted about as long as the original one.  I read elsewhere in these comments that Samsung made a replacement that uses ball bearings.  I'm making my own replacement from the original idler bracket, drilled out the bearing post, 3d printing a nylon pulley that'll fit on 3 "608" skateboard bearings, mounted to the bracket with 5/16"x2" bolt and a stack of washers... because why not?  :)