How exactly does that exclude a lot of web apps? Most web apps are very read heavy. And SQLite serializes writes to individual databases, not across all of them. It's trivial in SQLite to query across multiple databases.
Further, some form of write serialization is common to most database clusters: the most common cluster architecture is single write leader, multiple write replicas, which have the effect of serializing writes as well. Those clusters are all also taking advantage of the read-heaviness of applications.
Further, some form of write serialization is common to most database clusters: the most common cluster architecture is single write leader, multiple write replicas, which have the effect of serializing writes as well. Those clusters are all also taking advantage of the read-heaviness of applications.