As anyone who played CS 1.6 with the worst headphones you can imagine will tell you, if you need any fancy software or headphones to "help with gaming" that is a skill issue.

A good player will shit on you, even if you bust out the HD 800S and atmos.

These plugins are gimmicks and imho make everything sound DISGUSTINGLY bad.

That is where you are absolutely wrong. With proper counter EQ and custom HRTF that was made for your ear, a simple stereo pair cannot beat it.

It doesn't do any good if you wanna upmix stereo to 7.1, it adds nothing just blends stereo channels to rear, side and middle but if you leave it at stereo the HRIR still gives more advantage than unaltered stereo.

Which is why all the pro gamers use that software trickery and expensive headphones instead of whatever Headset brand they have a sponsorship contract with, am I right?

Again, if you need that shit to compete -> skill issue

That's what I don't get. It has option to upmix+downmix for exactly this scenario. But how is a HRTF supposed to do any better than originally stereo? Left is left and right is right.

Yeah, if you find one profile there that matches the best your own HRTF and taste for audio.

Start with oal_dflt.wav

But now you have HRTF delay that makes the sounds appear more accurate.
Without HRTF the sound would hit only the left ear but with HRTF the sound hits the right ear with a slight delay and it makes the "range and location finding" faster and more accurate.

Sound =//= visual and muscle memory.

If you think "bad sound" is why are getting shit on in competitive, you need to get off that copium and git gud :)

But HRTF doesn't know it's needs to add delay (since it doesn't have position info). It just just knows that this sound source has a 50% level on the RT and 10% on the LT. I suppose may be it always assumes to add a delay when this happens?