The marks on plastic aren't recycling categories, they identify the plastic resin. They partially indicate recyclability but the form is important. I don't think they are used at recycling centers which mostly go on common shapes. Products are supposed to now use solid triangle to reduce the confusion with recycling.

Plastic generally isn’t recycled that much, and many kinds of plastic cannot sustainably be recycled.

There’s a lot of automation in the space, and none of it uses the markers

>how they even achieve this at the town recycling center

They don't. A huge proportion is never recycled at all.