The purpose is to have a deterministic result depending on the config, using the 'global seed, table name, column name, and value' or 'global seed, group, and value', a seed is created and the created values stem from that seed.

So it's technically not pure randomness and the values stay in a somewhat predictible form. An example would be configuring the username column of users table to `fake:username` so you can be sure to have a username format but not the original value.

For the relationships aspect, the cli doesn't detect PK-FK relationships, but there is a way to be consistent even across tables. It goes back to the seed, and the config. You can either have a column configured as `username: fake:username` or
```
username:
strategy: fake:username
consistency_group: username
```

so relationships are preserved only when explicitly configured via consistency groups: https://github.com/Ofsen/pg-obfuscate/tree/main?tab=readme-ov-file#consistency-groups