This week, Andy Standford-Clark announced in a tweet the 20th anniversary of the first MQTT release. In those 20 years, it is clear that MQTT has become the de-facto standard for IoT. All major IoT cloud providers support MQTT, many popular IoT Platform vendors support MQTT, and survey results show MQTT is widely used for building IoT applications.
An interesting question to ask is “Why has MQTT has been successful?” What were the factors that led to the MQTT domination of IoT?