Not open source, but free for small teams: https://visualdb.com/

I am using Baserow (https://baserow.io/) happily.

Definitely try Baserow https://baserow.io/

I've heard good things about https://teable.ai/ for airtable-like flexibility. With more standardized CRM scenarios I'm going to try https://twenty.com/ with the next opportunity

Look at Grist.

You maybe justly concerned for it being an open source project that is backed by one small company that sells hosted plans.

The difference is that Grist is a core part of the French Government’s open source web applications La Suite

https://www.getgrist.com/

https://lasuite.numerique.gouv.fr/produits/grist

Fibery is free for small team (but not an open source).