It looks very plausible that stretching before you exercise doesn’t do much for you. Multiple older surveys suggested this.
Annoyingly, the studies linked in the previous paragraph are 2 decades old, and somehow I can’t find a large, well controlled, trial.
As an athletic trainer, I describe it like so:
Think of your muscles as a rubber band. If its cold, then its more at risk of snapping under load. To warm it up, you stretch it gently repeatedly. (Dynamic stretches) You don’t stretch it to its max and hold it there. (Static stretching) You’re just exhausting the elasticity. Saving static stretches for after activity keeps the rubber band from bunching up and sticking together as it cools down again.
An injured muscle could be described as being “colder” or like rubber bands stick together sometimes. And the best way to fix them is to work them back to normal in a controlled manor.