My understanding of the MVCC at work is that writes must effectively be serialized, but that pure-read transactions never have to block, as they can view a cons

My understanding of the MVCC at work is that writes must effectively be serialized, but that pure-read transactions never have to block, as they can view a consistent snapshot of the state at any time. This would imply read-scaling, but I don't see how this makes writes go any faster without reducing consistency. What am I missing?