Yes, of course we know that. But the main reason we haven't added chart widgets yet is because the data for historical charts must be prepared, collected and stored in a specific format. Drawing is not a problem when the data is prepared, but now the question is precisely in preparing the data.
In the near future, I think we will add charts in a fairly simple implementation, without storing historical data on the server side, just plotting in real time. But our goal is real historical charts with server side storing.