With SQLite you’re looking at third party extensions that compress the data, still in row-oriented format, and might rather inefficiently recover some benefit. But WAL probably does help with the write amplification above and beyond this.

journald-style logs really want a column store IMO. It would be highly entertaining to try something like ducklake with SQLite as the catalog — the whole stack is pretty lightweight and there’s support for inlining inserts in the catalog to avoid creating silly numbers of Parquet files.