Correct. DuckDB is really interesting technology, but it's not a direct successor to SQLite for transactional workloads. It's also very new: there's a LOT of new code in DuckDB on top of the (heavily fuzzed) SQLite parts.

(I use it personally, but it's not the same thing as what we're building with D1)

Also, for OLAP workloads there's Workers Analytics Engine. Analytics Engine is arbitrarily scalable as opposed to a D1-like solution - I can almost guarantee I've inserted more data into its internal variant (which is built on extremely similar underlying infrastructure) than just about any customer would think of doing, and it handles it like a champ.

Basically, we already have a product for doing DuckDB-like things, and the D1 architecture isn't great for high volume OLAP workloads.

Disclaimer: I'm an engineer at Cloudflare, but not on a developer platform team. I'm not speaking for our developer platform strategy or anything, I'm just commenting on how it looks from where I sit.