Hashtables and dictionaries are very popular in PowerShell Core. There are many cmdlets that you have already seen, such as Group-Object or Get-WinEvent, which work with hashtables. Hashtables are found when using splatting, and a special dictionary is used for the automatic variable, PSDefaultParameterValues, which defines key-value pairs for cmdlets and their defaults.
This recipe will show you another reason for preferring hashtables over other constructions: speed.