[HELP] Upgrading my PC

I bought this PC 5 years ago, today it struggles a bit on some games that require a lot of CPU. The graphics card is doing pretty well.

I'd like to update it, starting with the CPU, and switch to AMD, for better compatibility with Linux and notably to be able to encode videos more easily, I often edit long +4K videos.

Do you have any advice? The aim would be not to change my motherboard. And for the new components to last 5 years too? You can also advise me on graphics cards.

Here's the PC configuration:

- Processor type: Intel Core i5 9600KF (6 cores - 3.70 Ghz - Turbo 4.60 Ghz - Cache 9 Mo - TDP 95W)
- CPU cooling model: Be Quiet Dark Rock 4
- Motherboard model: MSI MAG Z390 Tomahawk
- Memory size: 16 GB
- Memory type: DDR4
- Memory frequency(s): DDR4 2666 MHz
- RAM brand: Gskill
- Graphics chipset: NVIDIA GeForce RTX 2070 SUPER
- Video memory size: 8 GB
- Graphics card reference: Gigabyte GeForce RTX 2070 SUPER GAMING OC 3X
- Case format: Medium Tower
- Case model: Zalman Z7 Neo
- Power: 550 W
- Power supply model: Seasonic Focus GX Gold