In the real world we are looking at things like RPO (recovery point objective) and RTO (recovery time objective). You need to consider HA and DR. It’s in these areas where SQLite does not scale.
That’s why I struggle to see the fit for SQLite in any sort of multi-user server environment. If you need the data to be durable, then the bigger DB’s have the tools. If you don’t need the data to be durable, just keep it in memory. I’m sure there are niches I am missing.