If money was no object sure I'd go speakers but since I am not a multimillionaire living secluded in the woods (yet) I need to be careful with my money. Therefore I prefer to buy a $400 pair of headphones that are more than capable of handling every modern mastering method at FLAC level (and some golden age mastering setups such as what the Beach Boys used) every couple of years instead of spending 15 thousand dollars on an equivalent speaker setup where I must sit in a specific spot and not move my head to ideally get the same sound as the headphones offer at all times. You may now call me poor.
I mean 15k USD would be about right if you want a new truly high end system for midfield listening in a decently large room, without audiophile bullshit. You could freely move your head and even yourself to a degree, of course, and as opposed to headphones the auditory image would stay in the same place, that's one of the points of having a good setup.
But that setup would be miles ahead of any 400 USD headphones and I don't think that's what this thread is even about, it seems to me that if we're talking about gamer dent (lol), the topic is HQ sound for your PC setup.
Firstly that's a nearfield situation, speakers are usually less than a meter from your head. This is important because sound volume lowers quadratically with the distance from the speaker, and as a result if you listen from a close distance, the difference between the volume of direct sound (from nearby) and the volume of reflections (from quite a bit further away, with exceptions like desk reflections) is higher. You get way less "room sound", less muddying of details from reflections simply by sitting close.
Secondly, as opposed to 10 years ago, there are now ultra cheap speakers with constant "narrow" directivity waveguides, like JBL LSR series or Kali LP series. These speakers radiate most of the sound spectrum in a 90°-120° cone, as opposed to 180°+ in standard speakers. This means that more sound is radiated towards you and less towards the rest of the room, further reducing the room effect. And a 90° cone is still large enough for you to move around a bit.
In my experience a contest between an approximately 400 USD pair of speakers like Kali LP-6 and a 400 USD pair of headphones does not have a clear winner. The headphones still win in the amount of audible detail, but they're not more realistic, the loudspeakers are more dynamic and when setup well to do a solid phantom center, produce a more real sense of space.