I'd be willing to bet that 99% of the sites/apps on the web have low to medium writes and reads. Developers like to plan on needing Facebook and Uber scale for their new task list and subscription box services though. SQLite benchmarks are impressive, they beat out commercial RDMS in a lot of comparisons.

As the header of your page denotes, things got significantly improved years ago with the addition of a WAL as the default mode rather than an exclusive write lock.

Also, I think most websites don't even need constant access to the DB, because the data doesn't change often.

Compile a static site from SQLite when someone enters new data, push it somewhere to be accessible and be done with it.