I must be doing it wrong. I've used a variety of different flashlights secured with the 2 fish products for over 10 years and haven't lost one yet. I've also used the wrist straps as a backup instead of zipties, and I think that worked once to keep me from losing a light.

And the removable batteries may take more effort to recharge, but they're a lot easier to change midride than the USB powered batteries in the dedicated bike lights. I'd rather carry around some spare batteries than a spare light when I go for longer rides.