Does a Raspberry Pi need a UPS to avoid SD card corruption?

In the past I’ve had trouble with corrupted SD cards when power was removed from a Raspberry Pi without shutting down the OS. But this failed attempt to build a UPS for the Pi has, as a side effect, tested powering down and back up over 50 times without a single failure. So are SD corruptions a thing of the past?

robDoes a Raspberry Pi need a UPS to avoid SD card corruption?