VisibilityTagHelper.cs

[HtmlTargetElement("div")]
public class VisibilityTagHelper : TagHelper
{
    public bool IsVisible { get; set; } = true;

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        if (!IsVisible)
            output.SuppressOutput();

        base.Process(context, output);
    }

    public override Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
    {
        if (!IsVisible)
            output.SuppressOutput();

        return base.ProcessAsync(context, output);
    }
}