I'd say room treatment is underrated. OTOH, it's not easy to clutter up a room with bass traps, panels, etc (WAF, etc) or very expensive to do unobtrusively.
In a "correctly" sized room, modes will be lesser, esp. in the bass. A treated room will attenuate these even further & help in avoiding spurious reflections that destroy imaging, etc -- the "magic". In an untreated room, speaker positioning is critical: not only for precise imaging at the listening spot, but also to limit modes & reflections. In a treated room, speaker placement is more a matter of getting imaging & depth correct, the treatment having dealt with the other (difficult) aspects.
In a "correctly" sized room, modes will be lesser, esp. in the bass. A treated room will attenuate these even further & help in avoiding spurious reflections that destroy imaging, etc -- the "magic". In an untreated room, speaker positioning is critical: not only for precise imaging at the listening spot, but also to limit modes & reflections. In a treated room, speaker placement is more a matter of getting imaging & depth correct, the treatment having dealt with the other (difficult) aspects.