Incorrect...a luxman c900u + m900u will drive any speaker at any price and can salvage many a undeserving turd posing as a high end speaker ( make it sound a whole lot better than it should). Boulder or Gryphon never knew how to design an amp better than Luxman. A heavier and a fancier looking chassis never meant a better amp.
Usually, Luxman is paired with speakers costing roughly up to 20k. If you get a top speaker, like the Magico M3, then the Luxman would be the sonic bottleneck. It’s best to have a balanced (near same level, minimizing bottlenecks) audio chain including cabling.