>Why does the author equate expensive with fragile?
He doesn't. His last paragraph literally starts "If buying an expensive product makes you a hostage of it"
Also keep in mind he's in Morocco. A $150 smart watch breaking is absolutely devastating when you earn $800 a month[1] and don't have access to the same warranty and support that people in the US do.
[1] This number is based a sample size of 1: a telecoms engineer who I was talking to (in fluent English) back in 2019 about hardware startups. It may not be indicative of the average salary in the region and is almost certainly above average.