Source that even "hard" brushing can damage enamel:

Abrasion. This is physical wear and tear of the tooth surface that happens with brushing teeth too hard, improper flossing, biting on hard objects (such as fingernails, bottle caps, or pens), or chewing tobacco.

https://www.webmd.com/oral-health/tooth-enamel-erosion-restoration

And here's the source for high fiber foods like apples helping:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6051571/

If you brush too hard you can chip enamel, but apples are too soft/mushy to do so, while still neutralizing cavity forming bacteria.

Now, that study didn't find that apples removed plaque, but it showed they prevent bacteria causing cavities and more importantly the study also required participants to only use apples as their sole dental hygiene regiment...

And I realize I said:

with just proper brushing or eating fiberours foods like apples, tartar really shouldn’t be accumulating to begin with.

But I never imagined people would think I meant only brushing would be all the dental healthcare they needed.

But man...

After this thread I am fully prepared to say I drastically overestimated my audience.

I can admit that.