i think the biggest issue is porn, not masturbating. shit stays with you, can make you view people differently and makes you tie sex to this fucked up dopamine-seeking cycle of switching from one thing to the next.
you'll find a lot of anecdotal evidence telling you that semen retention itself gives you more energy, confidence, mental clarity etc etc (proper research is lacking). I personally did it for like 3 weeks and i could see slight results i guess , but still gonna maintain that porn is the real problem. someone who is sexually active but doesnt watch porn and someone doing no nut will most likely find similar benefits, in my opinion