Math checks out except the problem is not randomly distributed - certain airports have a very much higher rate of lost luggage (LHR, JFK‚ CDG, looking at you!) and some types of luggage will be more prone to disappear.

https://www.primelinkinsurance.ca/blog/worst-reviewed-airpor...

This assumes an even distribution of likelihood this will happen, which is far from the reality. You can proactively reduce your risk — don't check in late, watch to make sure the check-in agent actually puts the tag on until you see it go down the conveyer belt, don't book tight connections, book even more generous connections in complex airports when you have terminal changes across the airfield from each other or airports with a poor reputation for mislaying bags on connections, use transfer airports that have been explicitly designed for rapid transfers (e.g. MUC). A general rule of thumb is if you are going to have to uncomfortably rush to make a connection, your bag is even less likely to make it.

Plus, should your luggage get waylaid, there are other things you can do to hasten its recovery: have a fairly unique bag that is unlikely to be mistaken by another traveller as theirs, clearly label your contact details inside and out in case the paper tag gets ripped off.