Better DACs/amps have noticeably lower noise floors than bad ones, yes. The 3.5mm jacks on my laptop and Nintendo Switch emit very audible white noise if I plug

Better DACs/amps have noticeably lower noise floors than bad ones, yes. The 3.5mm jacks on my laptop and Nintendo Switch emit very audible white noise if I plug sensitive earphones into them. It's important to distinguish price from quality here, though. For example, the $10 apple USB-C to 3.5mm adapter is known in the (non snake oil obsessed part of the) audiophile community for having very good characteristics for its price, including an extremely low noise floor. I use one on my laptop instead of the built-in 3.5mm.