I'd argue for using LevelDB or similar if I just wanted to store arbitrary data based on a single indexable value like TFA. That said, I'd probably just default to SQLite myself since the access, backup, restore patterns are relatively well known and that you can port/grow your access via service layers that include Turso or Cloudflare D1, etc.
Embedded KV stores like LevelDB are great for what they are, but I’ve often found that I’ll need to add an index to search the data in a different way.
And then another index. And at some point you want to ensure uniqueness or some other constraint.
And then you’re rewriting a half-complete and buggy SQLite. So I’ve come around to defaulting to SQLite/PostgresQL unless I have a compelling need otherwise. They’re usually the right long-term choice for my needs.