There are more alternative gems than mentioned in the readme

[DanielStevenLewis]

Here's a screenshot of the readme:

Here are additional alternative gems I found:
https://github.com/fnando/defaults
https://github.com/makandra/has_defaults

I'm leaning towards using default_value_for over these alternatives because it has more GitHub stars so it's probably more likely to continue being maintained.