Yes, that's the point I'm making. If SQLite didn't ever struggle with databases in the GB ranges, then there wouldn't be much call to replace it with DuckDB. The fact that there's significant value in an OLAP RDBMS suggests that SQLite is falling short.
The problem is not SQLite struggling with databases in GB range. It does that with ease. OLAP requires a different database structure, namely column storage (preferably with compacting / compression / and other algorithms).
That is DuckDB its selling point. You want data analyzing, you go DuckDB. You want oltp you go SQLite. Or combine both if you need both.
Even postgres struggles with OLAP dataloads, and that is why we have solutions like TimescaleDB / postgres plugin. That ironically uses postgres rows but then packs information as column into columns row fields.
That does not mean that postgres is flawed working with big data. Same with Sqlite... Different data has different needs, and has nothing to do with database sizes.
