Welcome to the Airtable community!
Many people would like to have interfaces be public. And Airtable stated that they understand that people want that feature in one of their recent “Community AMA” announced in this post.
Airtable has a history of releasing new features incrementally. When enough of a new feature is ready, Airtable release it, even if it doesn’t yet have all the bells and whistles.
On the other hand, if you really need a particular feature on the free plan, Airtable might not be the right platform for you. Airtable uses its free plan to let people get a taste for the platform, but reserves many of its most powerful features for Pro and Enterprise users.
Wow, amazing that this is not a feature yet 😳. Just started investigating Airtable and created some dummy content to test things and then an interface to display it. I saw the share button on the interface and assumed "ah good, they have the ability to share it publically" but when I had finished and wanted to show the boss the potential of Airtable I was perplexed to not see a public link option. It's not even a pro feature!!!