The GC can also run incrementally to meet deadlines. It’s not like a Java GC. It has been used in microcontrollers. People should probably learn more about it before shooting it down based on the word GC.
Java GC also has been used in microcontrollers, with soft real time deadlines, there are plenty of JVM vendors out there, including a couple that are only focused on embedded development like PTC, Aicas, Gemalto, microEJ, Virtenio.