you should be squashing bugs related to your business logic, not core data storage. Local data storage on your one horizontally-scaling box is a solved problem using SQLite. Not to mention atomic backups?
What is more likely, if you are making good decisions, is that you'll reach a point where the simple approach will fail to meet your needs. If you use the same attitude again and choose the simplest solution based on your _need_, you'll have concrete knowledge and constraints that you can redesign for.
e.g. worry about what makes your app unique. Data storage is not what makes your app unique. Outsource thinking about that to SQLite
Surely it does? Otherwise you cannot trust the interface point with SQLite and you're no further ahead. SQLite being flawless doesn't mean much if you screw things up before getting to it.
Regardless of whether most apps have enough requests per second to "need" a database for performance reasons, these are extremely important topics for any app used by a real business.