Sometimes it's nice to not manually write a regexp to find all of the variants of every word or deal with arbitrary ordering of substrings. And if you're using SQLite and fts5 is installed, why not just create a virtual full text search table with one command and use that? With a small enough corpus, it's a meaningless distinction to bikeshed about the implementation: the easiest solution to build is the best. 500MB of disk space for a pet project that gives you convenience is a terrifically small amount of storage. I have videos that I recorded on my phone that take up more than double that.