You can also schedule pinning and unpinning of posts from a community if you're the moderator, making it possible to schedule for example weekly/daily threads as well as their pinning and unpinning.
Another great feature is the possibility to select multiple communities to post into.
Because Lemmy doesn't support OAuth and this is actually the only way to do it. Hopefully only temporarily. Edit: The thing's open source, you can check that I don't do anything with the password, I only use it once to login to the api and get the token, pretty much the same as I would do with OAuth.