No, pocket screws are not the strongest of joints. They’re stronger than a plain butt joint but weaker than a tenon, but the OP is talking about a frame for his light. It doesn’t need to hold much weight at all. Like I said in my post, the ‘best’ joint depends on the wood, the application, the tools available and the individual’s skills.
Fine Woodworking did a ‘joinery shootout’ several years ago - you may be surprised to learn that a glued pocket screw joint beat a domino joint. Their test was for a 90º frame joint that was stressed by holding one member vertical and pushing down on the perpendicular member (think of the corner of a picture frame.) I’m sure the results would be different if you did a straight vertical load at the joint or loaded the joint on a different axis.
I used pocket screws in my stand. Of course it was just for the corner braces...

I also used half lap, some dowels and mortise and tenon joints.