Objects are cheaper than Arc<T>. Otherwise using GC would suck a lot more than it does today (for certain types of data structures like trees accessed concurren

Objects are cheaper than Arc<T>. Otherwise using GC would suck a lot more than it does today (for certain types of data structures like trees accessed concurrently it is also a massive optimization). Python also has incomparably worse performance than Java or C#, both of which can do many object-based optimizations and optimize away their allocation.