I dont do drugs, so this is the closest thing. not to mention you gain more than you lose

To me, it depends on the maturity of planar headphones (which hit their peak in terms of technological application a few years ago). most planar headphone manufacturers have been able to produce very good sound quality and probably there aren't many other ways to improve its performance. for dynamic, it had peak many years ago. so yeah, until a new class of technology that can have different sound quality than dynamic and planar, I would think we had reached the peak. Electrostatic? Not too common and IMHO not too different from planar sound

Interstellar