Free is more than just $0, it's about freedom.

Free software allows you to adapt it to your needs, be scrutinized by the world as it's transparent, and offers no barriers of entry other than technical.

If they ask for money I usually give it to them, but it's usually not the main motivation to create the free software in the first place.

In some cases they need some kind of business model to continue, like GrapheneOS, and that's usually covered by things like patreon, etc.