did you look at baserow ~~and~~ ~~nocodb~~~~.~~
They are not note taking applications. But you can use both obsidian and baserow combined as an alternative to notion ..IMHO
Sure thats a good approach We also use KOOPJS sometimes delivers vector tiles or Esri GEOSERVICES featureserver REST API from postgis
Also use nocodb for spreadsheet like editing of PostgreSql database and exposing graphql and REST API https://www.nocodb.com/
This also works with OGC GPKG which is Sqlite
Airtable is afaik the leading web based no code relational database. A couple of open source alternatives that I haven't tried are https://www.nocodb.com/ and https://baserow.io/.
You have some options.
Serene looks like it might be what you're looking for, but will require some C# / ASP.net knowledge. They have a ton of information on their website and it's open source.
The other two are easily spun up in a docker container and are more low code / no code.