> especially if users are still in the tens of thousands

I've got unit tests over business methods backed by SQLite that say otherwise.

The biggest benefit with SQLite is being able to ship your customers 1 self-contained binary distribution that "just works". Anything beyond this and we are talking about nasty customer-owned database instances or us shipping docker containers and hoping the gigantic abstraction bubble doesnt pop on us.

I've shipped multiple products that are backed by a SQLite database for core functionality (authentication, billing, and permissions mostly), and individual SQLite databases for customer data.

It has made it incredibly simple to downgrade and delete customer data when they request. The application kills the billing profile, and emails the administrative email for the organization a link to download and delete their data.