Why the Teensy destroys the Arduino Uno, Mega, and even Portenta in Memory, Size, and Sheer Power

Although it is a little dated, this video from Zack Freedman on Youtube explains the benefits of the Teensy microcontrollers, why the Teensys outperform the Arduino Uno, Mega, and even the Portenta in memory, size, and sheer power, and how the Teensy can be programmed using the Arduino IDE using the Teensyduino Board Manager.