Need help on upgrading to a current gen phone

I'm currently using the Xiaomi Redmi Note 9 as my main phone and a Samsung A04 as a backup.

It's been five years since it was bought and it's age is really showing. Heats up quite a bit after a 20-25 minute of gaming, charging is slower and the screen is less responsive.

It still works and is never opened but I have some cash now, so what should I get next? Price range is about $250 - $400.