Comment by WalterBright

Flying at near supersonic speeds at high altitude with a swept wing airplane is quite different from low and slow with a straight wing and thick air. Jetliners have a rather small envelope at altitude where the airplane will fly, things like overspeeding it will cause it to go out of control.

A fair amount of effort goes into designing the cockpit so it feels to the pilot like a low and slow aircraft, but it is not the reality.

For example, jetliners are unstable and require a yaw damper.