Upgrade GPU from NVIDIA GeForce GTX 970, what's compatible?

[Gg9988]

My oldest son built my youngest son a PC many years ago but he now he is wanting to upgrade his old GPU to one that is better for his current gaming. I'm limited on what might be compatible unless I upgrade the CPU, which I don't mind so long as overall it doesn't get crazy £££... so looking for recommendations as to what to upgrade to with an absolute MAX budget of £500 (less if possible) -not expecting miracles or to be the best obviously, but just needs to feel like a real improvement on what he currently has when gaming.

He mostly plays Siege and Apex and his biggest complaint is that he's not getting anywhere near the best (fps) for his new screen that he recently bought with his birthday money, because it's a QHD Ultra Wide 1440p (3440*1440) 165HZ

Current spec is:
Motherboard: ASRock a320M- HDC R4.0
GPU: NVidia GeForce GTX 970
CPU: AMD Ryzen 3 3200G with Radeon Vega Graphics- 3600mhz, 4 cores
Screen: KOORUI 34 Inch Ultrawide Curved Gaming Monitor, 165Hz, WQHD 1440P, 1000R, MPRT 1MS, HDR 400, 2x HDMI 2.0, 1x DisplayPort 1.4
Memory: Corsair VENGEANCE LPX DDR4 RAM 32GB (2x16GB) 3600MHz CL18 AMD Ryzen Computer Memory
Storage: SSD:Samsung 980 1 TB PCIe 3.0 (up to 3.500 MB/s) NVMe M.2 Internal Solid State Drive (SSD) (MZ-V8V1T0BW)
Operating System: Microsoft Windows 11 home
Power Supply: Aerocool Integrator 700 W 80+ Bronze Certified ATX Power Supply

Any advice would be great, thanks.

 

[COLGeek]

What is the make and model of your power supply? That has a huge impact on your options.

 

[Gg9988]

What is the make and model of your power supply? That has a huge impact on your options.

Oh yes, I forgot that bit.

Power Supply: Aerocool Integrator 700 W 80+ Bronze Certified ATX Power Supply
Thanks

 

[COLGeek]

Given the overall system config and budget, try this on for size.

https://www.amazon.co.uk/MSI-GeForce-VENTUS-BLACK-Graphics/dp/B0CBK7BRL9?crid=2O5IK2J8Y9EDF

This would be a substantial upgrade over the current GPU while not putting the rest of the system "out of balance" (I don't use the term bottleneck) too much.

 

[Gg9988]

Given the overall system config and budget, try this on for size.

https://www.amazon.co.uk/MSI-GeForce-VENTUS-BLACK-Graphics/dp/B0CBK7BRL9?crid=2O5IK2J8Y9EDF

This would be a substantial upgrade over the current GPU while not putting the rest of the system "out of balance" (I don't use the term bottleneck) too much.

Thank you.
I had looked at this before and saw so many posts that all talk about bottleneck - which makes almost every decent GPU off-putting, hence I went down a rabbit hole of maybe changing the CPU. I Think I'll get this one as you suggest - and if I need to upgrade something else later, then so be it.

thanks.