Spec for a Dac are the maximum values it can use. Let’s compare with a car, it is not because the max speed is 300km/h that you need to drive that speed to enjoy your travel…
There is no need to over sample a cd (my point of view) because you won’t add information that are not here…
You can get high Res files though, Qobuz, tidal or other, but not sure you can hear the difference, because of your Dac, amp, speakers, room, and your ears! For me most of High Res is marketing, even if thecnically it is better. A lot of users buy high Res music to listen on a low end system or even via Bluetooth and claim it is fantastic 