Also some the Mono issues were related that they never had Microsoft's budget for implementing a bleeding edge runtime.
From Computer Science point of view RC is and will stay a GC algorithm.
https://gchandbook.org/contents.html
https://sites.cs.ucsb.edu/~ckrintz/racelab/gc/papers/levanon...
https://sites.cs.ucsb.edu/~ckrintz/racelab/gc/papers/AzaPet-...