I (also) have lots of external drives [which I NEVER travel with.]
10-12 4 TB drives, takes up a fair amount of space in a carry-on. You never know when a "zealous" TSA goes on a power trip, and decides he/she wants further inspection. In the wrong hands, data could be lost.

There are services, that allow you to back-up your data (inexpensively(?)) in the CLOUD. [Extra back-ups are good in general.

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