We plan for car crashes by wearing seatbelts, buying insurance and some even buy cars based on safety features. Carrying an SSD seems a little over the top to me when there’s cloud backups, but perhaps there are reasons the poster doesn’t trust cloud services.
And FWIW when I fly I keep my passport, phone and medicine on my body at all times. While the odds of a crash are low it’s better to spend 15 seconds preparing (especially since there’s barely anything else useful to be doing while in the terminal or airplane).