Tesla is going (back) to EV motors with no rare earth elements., page-37

You are probably correct. the question like in everything is a side by side chart of the plus and minuses. Price and absolute max performance are only two of many points.
True but look at how much companies like BMW, MB, GMC Toyota, paid tesla for the non PM design's it was multiple billions. On negative side a few % less efficient bigger heavier. On positive 150 year old tech that had lots of room for improvements and had no single point of supply problems.

Many people think BYD will pass them in 2023

Last time I looked non REE motors were about 94% efficient, PM 96%. If half the money was spent improving the Non PM that was spent on PM probably only 1 %. Many of the improvements in PM design Like stator design ports easily to non PM motors.

References please for the less efficient. Or at least tell us what it is. 1 % 2% 5%?