> Whatever the app or the device, accessing a register is always going to be faster than random places in RAM, which is always going to be faster than fetching

> Whatever the app or the device, accessing a register is always going to be faster than random places in RAM, which is always going to be faster than fetching something on disk and even moreso if we talk about fetching stuff over the network. The network is special: the time it takes to fetch something over the network can be arbitrarily large, or even infinite (this can also apply to disk when running over networked filesystems), while for registers/RAM/disk (as long as it's a local disk which is not failing) the time it takes is bounded. That's the reason why async/await is so popular when dealing with the network.