It is recommended to use the most recent API versions.
There is an opt-in bicep linting rule you can use to help alert you to where bicep is using older api versions. https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/linter-rule-use-recent-api-versions
I would also recommend looking at the API changelog in the docs, this tells you explicitly what values have been added/changed. New additions are a typically a signal of new features that are available in that service.