Best gaming phone under $600 right now? Need real opinions

Hey everyone, I've been gaming on my phone for about two years now, mostly Call of Duty Mobile and Genshin. My old Samsung is starting to lag during heavy fights and I'm ready to upgrade.

I keep going back and forth between a OnePlus and a newer Samsung A series. I've heard OnePlus phones run cooler and have faster touch response, but Samsung has better screens and updates last longer. Battery life matters a lot too since I game for hours at a time.

Budget is under $600. I don't care much about camera quality, I just want smooth gameplay, good cooling, and a battery that lasts through a long session without charging twice.

If you've used either brand for gaming, what was your experience like? Did you run into overheating or lag after a few months? Any model you'd tell a friend to avoid?

Would really appreciate advice from people who actually game daily on their phones, not just spec sheet comparisons. Thanks in advance.