Paul White shares some advice:
Microsoft encourages us not to use the datetime data type:
Avoid using datetime for new work. Instead, use the time, date, datetime2, and datetimeoffset data types. These types align with the SQL Standard, and are more portable. time, datetime2 and datetimeoffset provide more seconds precision. datetimeoffset provides time zone support for globally deployed applications.
Well, ok. Sensible and well-informed people might still choose to use datetime for performance reasons. Common date and time functions have optimised implementations in the SQL Server expression service for the datetime and smalldatetime data types.
Paul has posted the full article on X.