It does wear down over time.  It's only on a microscopic level, but noticeable.  The new scratcher has a slight plateau where the nozzle slides off.  The old scratcher has the plateau worn down.

Some new ideas emerged, like lengthening the handle, making the scratching head convex, either keeping the spikes parallel or making the spikes radial.  The scratcher has proven useful for scratching many other body parts & makes a big impact on the pet hair situation.

A convex scratcher was designed.  The spikes are farther apart.  

The rear scratcher is not to be underestimated.  The longest handle the Ender 3 could print ended up being 270mm.