It's not relevant or an indicator of power that this example requires ten lines of SQL. This presentation just uses SQLite's builtin full-text search system [1]. Of course it's going to require less code to call a library than to implement it.
Relevant because "building a full-text search engine" is solved using SQLite just as much as it can be solved by writing Python on top of lxml and py-stemmer.
SQLite is no heavyweight dependency àla Apache Lucene. It also helps that it is bundled in billions of Android and iOS devices.
I'm sure there's some pypi package that has a full search system you can download. For that matter, there's the python sqlite package. It's irrelevant that it's ten lines of library calling code when you're comparing it to a toy implementation.
[1]: https://sqlite.org/fts5.html