When you dance with the devil in the pale moon light, don’t presume you will change the devil - the devil will change you.
Honestly, the only real way to make sustainable profit on Amazon is to have a branded, premium product that you are the sole supplier of, and with your own demand. (And is exceptionally hard to counterfeit because Amazon doesn’t seem to care at all about counterfeit anything…)
Everything else is commodity chasing, and if you have something now, you best be chasing next as hard as you can… because your position is as fleeting as your profits.