If you prefer a clean, "Google Pixel-like" experience over Samsung's heavy software, AOSP-based ROMs are your best bet.
Eliminate Samsung’s older, heavier background services for a snappier UI and better screen-on time. samsung s9 plus exynos custom rom
AOSP ROMs degrade stock camera performance. Download a compatible GCam (Google Camera) port for Exynos 9810 to get night sight and superior HDR processing. If you prefer a clean, "Google Pixel-like" experience