Low end reverberation is very real in live sound. Some of those same issues that plague audiophiles are even more present on stages and venues that are not acoustically treated. The issue compounds when you have hollow stages, monitors, guitar/bass cabinets, and dozens of mics on the stage circulating those low end frequencies back to the board creating a low end feedback loop. When you have larger groups like TOP with horn sections, singers, etc. That is more mics and monitors on stage compounding the challenge for the sound person.