Comment by kukkeliskuu

Both of your statements are true.

But in practice we are rarely interested in single writes when we talk about consistency, but the consistency of multiple writes ("transactions") to multiple systems such as microservices.

It is difficult to guarantee consistency by stopping writes, because whatever enforces the stopping typically does not know at what point all the writes that belong together have been made.

If you "stop the writes" for sufficiently long, the probability of inconsistencies becomes low, but it is still not guaranteed to be non-existant.

For instance in bank payment systems, end-of-day consistency is handled by a secondary process called "reconciliation" which makes the end-of-day conflicts so improbable that any conflict is handled by a manual tertiary process. And then there are agreed timeouts for multi-bank transactions etc. so that the payments ultimately end up in consistent state.