Ah, a healthy dose of reality. Much appreciated...
Speaking as an excessive chalker. I have had tips last for many many years. One M/H Morri, which eventually compressed to Hard, lasted near 10yrs, (top layer finally popped off). My explanation...?..., I don't use shaping tools or sand paper. ...ever. Either that or there's some alternate dimension centered on the ferrule on my Z2 shaft that prevents the application of chalk from wearing down my tips.
Talking about Master chalk here and to some extent Silvercup and some other chalks that saw occasional use, it does have abrasive added I believe. The same basic chalk was used on our hands and our cue tips for opposite results. When the abrasive in the chalk doesn't damage the cue ball to a noticeable degree except over years and then we get a universal shrinkage that may be more due to dent and rebound popping tiny flecks off of the cue ball, it would seem that the embedding and some sliding must occur between the tip and the abrasive in the chalk. Some claim that chalking even shapes the cue tip.
This all seems reasonable and intuitive to me other than chalking cutting fast enough to keep the tip shaped. The issue for me is that I too have used a single tip on a shaft for years. Intuition and logic don't seem to match what use proves.
I don't have answers. I am confident my small stock of sorted Elkmaster tips are going to last beyond my lifetime. Wear is negligible when a good tip is on a stick and we don't jack with it all of the time. I have long ago given up on answering why chalk doesn't damage it more. Why doesn't really matter anyway, what is important is what happens, and what doesn't happen.
Hu