Home Assistant is not required, that’s just another tool you can use with MQTT once you have the bridge setup. @xAPPO seems to have had an easy time of getting the bridge running on an rPi so you might want to check out the ThingBox image as it already has an MQTT broker built in.
MQTT is super handy for integrating all sorts of disparate systems. Once you have the MQTT bridge running with SmartThings, you can directly tie that to other platforms like EventGhost, Home Assistant, OpenHAB, etc. Events that happen in one environment can be acted upon in the other environments, providing a “glue” to tie all the systems together. It’s worth looking into and MQTT is dead simple to setup.