Honestly, if you're dropping $1500, I'd definately recommend just sticking with Nvidia. I've had way less headaches with their drivers over the years, and for 4K gaming, you realy need that stability so your system doesnt just crash or have wierd artifacting. Basically, you want something that's built like a tank and is known for solid reliability. - Just get any of the high-end series cards from them.
- Look for the ones with triple fans and massive heatsinks to keep temps down.
- Make sure your power supply is top-tier to avoid any safety issues with power spikes. Idk, maybe some people like to tinker with settings more, but I prefer things that just work out of the box. So basically, go with the big name brand and you cant go wrong. Better to be safe than sorry when you're spending that much cash on a single part, anyway... hope that helps!

RTX 5090 is the best choice.

RTX 5080 for budget around $1500.