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.
I cant find a definitive collection of peer reviewed material that says what stretching actually works. I just want to save money instead of buying a machine to suck my balls for me. Is that so much to ask?