Commercial planes won't fly faster than 600mph despite there being technology that makes it possible and this is why

Commercial jets generally won’t fly faster than about 600 mph even though modern aircraft could theoretically handle higher speeds. The article notes typical cruise speeds around Mach 0.82 to 0.85, roughly 630 to 650 mph (1,014 to 1,046 km/h), while the aircraft’s structural “safe” limit is estimated at about Mach 0.90 to 0.95. The biggest constraint is drag: as speed rises, resistance and required thrust climb sharply, with drag scaling in a way that drives much higher fuel burn and therefore higher ticket prices. The piece also cites thermal structural limits and passenger comfort, since higher speeds would increase vibration and make the ride rougher, like a less comfortable ride experience.