The last point isn’t so dramatic. There is version control for notebooks, and better version is coming (right now it’s in preview - code name - Projects, it’s in official docs). Tests are possible - either Nutter from Microsoft, or home grown (about 20-30 lines on top of built in unittest). Deployment is also not so complicated - there are tools (provider for terraform, cicd-templates project, Databricks-cli, etc), you can refer MS Learn for short course about CI/CD for Databricks and Azure DevOps, etc...