The nvidia driver is working fine. Also the nvidia audio is functional, it’s only used for external monitors. Your internal audio is driven by an intel sof-soundwire device with Cirrus Logic cs35l56/cs42l43 codecs. Might be you have to upgrade the firmware for it. https://github.com/thesofproject/sof-bin/tree/main/v2.9.x/sof-ipc4-tplg-v2.9
Your webcam is not supported yet by the mainline kernel so you’ll have to install the driver manually, should be the intel-ipu6-dkms package.
The Arch people collected some info about your notebook model:
https://wiki.archlinux.org/title/Dell_XPS_16_(9640)