Use CommunityToolkit.Mvvm in wpf.ui library

[IvanDmitriev1]

What about to use CommunityToolkit.Mvvm RelayCommand instead of those that already exist?

[pomianowski]

The Microsoft Toolkit has been replaced with the Community Toolkit in bbaebb8

As for RelayCommand, this is cannot be realized because WPF UI cannot depend on the Community Toolkit by default.
The user may don't need to use additional libraries, so there should be as few of them as possible.