Actually in many cases
A simple text file may be a much more efficient and simpler. Databases, or more precisely, relational databases, are made for the case when you have lots of tables that "link" together forming some sort of relation.
However there are other applications where you want to handle data. One example I came across recently was the "Portierungsdatenbank Festnetz", which is a large table storing what operator handles what number(-prefix). It has over 100 Million datasets. Using this with a traditional database is incredibly slow, as even with indexes, looking up a data set will take a good fraction of a second. However if you simply sort it once, then sort the updates and simply mix them into your main file, you can work with it faster than your harddisk can handle the data... and since those are linear reads, not seeks, your harddisk will be at peak speed. And all that with text files you can simply edit with a text editor.
It often makes sense to look at alternatives off the hype.