Please teach me how to configure my containers so SQLite can scale horizontally.
Other databases have the same issue, try having multiple database containers (without massive speed losses). If application is bound by the performance of the front end, this is a problem, but those really are not what SQLite was intended for.
In the case of database bound applications, SQLite is just as good as any other database, which despite having a client server model can typically only handle a single operation at once.