Yes and no. LXR is a highly optimized deferred and coalesced reference counting (amongst many other optimizations) GC and it looks nothing like the RC implementations you see in other languages like Python, Nim, Swift, etc. So yes, reference counting can be performant, _but_ only if you are using a deferred and coalesced implementation as otherwise the simple implementation requires atomic operations (though compilers could optimize it to use non-atomic operations when it's sure semantics are preserved).