Is grain-free dog food actually bad now or just a scare?

Been feeding Buster and Daisy standard kibble most their lives. Works fine. Then my neighbor starts telling me grain-free is the way to go so I switched Buster for a stretch.

Now Im seeing headlines that grain-free causes heart problems? DCM or something? Then somebody else says the study was garbage and the FDA dropped it.

Folks overthink this. But also I dont want to be the guy who ignored something real.

Both old girl and old boy seem fine either way. Energy good, coats look decent, no complaints from them obviously. Buster will eat a shoelace if you let him so hes not exactly picky.

Just genuinely confused whether this grain-free thing was a real finding or one of those panic cycles that fades out in two years. Seems like every few years theres a new thing to be scared of in the dog food aisle.

Anybody actually follow this situation close enough to explain what we know now?