Scarlett is not really designed to be a good playback device, it's meant to be a recording interface.
Highly disagree here. The Scarlet2i2 is designed as a professional audio I/O interface. It has both high quality inputs, plus outputs. It's DAC is of high quality and is perfect for music production and powering audio monitors, where high quality audio and true-to-life reproduction is required. And is grounded very well.
This includes the headphone port, which runs off the same DAC and is used for headphone monitoring.
If u/Hashtwister has a Scarlet available to use, I would highly recommend just using that over anything else.
However, for OP, I would say: If you are using HyperX headphones, you likely won't really notice a difference. Gaming headsets aren't that great at proper audio representation.
For the Scarlet, I'd recommend looking at getting also some proper audio headphones (such as the Senheisser DT770) - though it will certainly take some time getting used to the flatter (more real) audio experience! :)
Sidenote: Even a GoXLR is a good option here, as the DAC is also of high quality. However, again, matching with proper headphones would be better instead of using gaming headsets.
The USB/Audio Jack debate is not a real debate. Some built in audio-jacks can be rubbish, some can be good. It very very well depends. But often always, an external higher quality DAC will be better.