The nvidia-persistenced group/user is created by the install script in the nvidia-utils package (or equivalent if you use one from the AUR). Reinstalling nvidia-utils will recreate the needed nvidia-persistenced group/user. Without reinstalling you can directly run both commands referenced in the link:
sudo getent group nvidia-persistenced &>/dev/null || groupadd -g 143 nvidia-persistenced sudo getent passwd nvidia-persistenced &>/dev/null || useradd -c 'NVIDIA Persistence Daemon' -u 143 -g nvidia-persistenced -d '/' -s /sbin/nologin nvidia-persistenced
Whether you’ll want to enable/disable the nvidia-persistenced service ultimately depends on your specific (NVIDIA) hardware. I have mine disabled on a non-hybrid single GPU machine without any issues.