[pantalaimon]

It adds quite some space and probably costs as much as the MCU.

[kabdib]

Yeah, paying thirty cents for a capacitor to coddle a ten-cent MCU doesn't make a bunch of sense. Much cheaper to teach your software folks how to write transactional updates to that flash. Typically you pay a small speed penalty to get update atomicity (in addition to having a more complicated implementation).

[keithnz]

not as simple either, you still need to detect that the power is gone or fading independent of the capacitor...which all adds up