Headphone users benefit a lot more from a dedicated sound card, especially if they have an AMP on them.Why add a sound card at all? The built-in audio on modern motherboards more than meet the needs of most users.
actualy most people who had dedicated soundcard already moved into better external solutions, coz they are better as you can move it around between devices and as a bonus, you got zero PC noise, you also dont need to to worry about drivers with themHeadphone users benefit a lot more from a dedicated sound card, especially if they have an AMP on them.
To answer the OP: I can't speak for Win11, but my Creative Sound Blaster Z works fine on Win10, and Creative has a number of newer products I'm sure are supported. I would expect most things that have a Win10 driver will run on Win11, though I'd clarify that with the OEM before a purchase regardless.
As someone who's had a sound card in some form or another in the past two decades, the only "strange issue" I've had is the occasional freeze if mucked around with the actual hardware. But I doubt that was because of the sound card. It was probably just me touching it.Try onboard sound first.
If you want better, buy new; no telling why a seller wants to get rid of a card.
Lastly, sound cards are tightly interwoven with pc functions.
In the past, there have been many strange issues with sound cards.