Looking for Guidance on PC Upgrades: GPU, CPU, and More

Hey everyone! I'm in need of some advice on upgrading my PC, which was a generous gift from my brother a couple of years back. As I'm not particularly savvy with PC specs, I got the information from UserBenchmark and discovered that my current GPU is an RX 580.

I'm considering upgrading my GPU first and have my eyes on the Radeon RX 9070 XT with 16GB GDDR6 since it gets a lot of positive mentions. However, I've heard Nvidia GPUs are quite overpriced at the moment, so I'm leaning towards AMD.

Beyond the GPU, I'm not certain what else should be prioritized. I've thought about:
- Upgrading the CPU
- Replacing the motherboard
- Possibly RAM, although the prices seem kind of steep right now, making me hesitant to invest.

Is there anything else I might be missing before making a decision?

Just to give you a bit more context, I mostly stream on Twitch using OBS and play games like Dead by Daylight, Valorant, Resident Evil series, Wuthering Waves, and enjoy co-op games in general.

When I upgrade, I want to ensure that it's a significant improvement that will last me quite a while.

I'd love your thoughts on:
- If the RX 9070 XT is a smart choice and really delivers the best value as suggested online.
- What I should prioritize upgrading first.
- Whether it's wise to wait on RAM.
- Any other components I might have overlooked.

Thanks a lot for your help! By the way, my current setup includes a Mateview GT monitor without a soundbar, which is starting to show signs of aging. I can afford a solid PC setup within a budget of 1.5-2k euros, but I'm considering postponing a monitor upgrade until I absolutely must. Appreciate any advice you can throw my way! Happy Sunday!