Flat bench destroys my rotator cuffs 😭
Very likely you’re benching incorrectly. In other words, “bodybuilding-style” technique.
Elbows flared, and with an improper set up: shoulders not behind the chest and a flat-back position.
Too many spout horseshit about the arches usually observed on successful/high-level bench pressers. Sure, this can be taken to an extreme, but make no mistake. A tight and prounced arch is the correct and advantageous biomechanical shape to achieve.
Pinched upper back, pecs higher than your shoulders and the elbows pulled into the sides of the body on the eccentric portion of the stroke.
With this, most wouldn’t ever experience much of any shoulder issues.