Why is SYSDATETIME() slower than SYSUTCDATETIME() In SQL Server?

Consider the following code that calls SYSDATETIME() 10 million times in a loop:

GO

CREATE OR ALTER PROCEDURE #p_local AS
BEGIN
	SET NOCOUNT ON;

	DECLARE @dummy DATETIME2(7), @loops INT = 0;

	WHILE @loops <= 10000000
	BEGIN
		SET @dummy = SYSDATETIME();