Telerik TextBox for string is nice but what about something like [DataType(DataType.MultilineText)] for TextArea?
Forms should really come with Text Area. It seems like a good one to do next.
Blazor Form Overview | Telerik UI for Blazor
An idea is that perhaps other data type annotations could be used - perhaps Date, DateTime, TIme can switch different date/time pickers, Html can generate the HTML editor, Password can set a textbox with the Password type