cause i need a locked Bootloader or otherweise WhatsApp (which i unfortunately need) wont work, but coming from a rooted rom, unrooted android is unbearable> You can keep your bootloader unlocked and rooted and still get WA to work. Check this xda post: https://xdaforums.com/t/problem-with-whatsapp-and-bootloader-unlock.4642218/post-89755699

I have PIF and LSposed installed with denylist active for WA, Gplay and GplayServices. It’s working.