How to fix flickering and lagging issues on iPhone 16 Pro Max?

I recently bought the latest Apple phone in December, and unfortunately, it has not lived up to my expectations. Despite its high price, the performance is subpar. The battery life is disappointing, and the camera quality is not as advertised. Additionally, I've encountered several software glitches that have made using the phone frustrating. Overall, I feel that this phone does not offer good value for money.

I would like to have this issue fixed as it makes my life more difficult.

As a 20 year old I've only had iPhones/ apple ecosystem, however I can no longer justify the price in these phones/ products. I got this phone less than 5 months ago and it has already giving me issues and yes, it has the software fully updated to 18.4.

[Re-Titled by Moderator]