How come the left side of the deformer sets window is always empty?

I am learning about maya deformers. I am stuck on this specific section though.

I am following this series here, The Maya Toolbelt - Bend Deformer, at around 10:17, he selects a deformer and opens the “deformer sets” window (via windows > relationship editors). The left side of his window always has a deformer listed in it but on my end end, that same left side is always empty, just the right side is populated with items.

Anyone know what could be causing this? Am on Maya 2025.3/win 11.

I have a feeling that’s because your deformers default to the new “Component Tags” system instead of the legacy “Deformer Sets”.

See: Help