Comment by mlwiese

There is movement away from stop-the-world GC, but not to reference counting. The movement is towards better GC.

The language Go has sub millisecond GC with multi-GB heaps since 2018. See https://blog.golang.org/ismmkeynote

Java is also making good progress on low latency GC.

Reference counting can be slower than GC if you are using thread safe refcounts which have to be updated atomically.

I don't want to have to think about breaking cycles in my data structures (required when using ref counting) any more than I want to think about allocating registers.