I had the same exact problem. Here is a workaround: Create an xml file containing the following minimal content. Then change the extension of the file from MyReport.xml
to MyReport.rdlc
in order to have rdlc extension.
<?xml version="1.0" encoding="utf-8"?>
<Report
xmlns="http://schemas.microsoft.com/sqlserver/reporting/2008/01/reportdefinition"
xmlns:rd="http://schemas.microsoft.com/SQLServer/reporting/reportdesigner">
<Width>6.5in</Width>
<Body>
<Height>2in</Height>
</Body>
<rd:ReportTemplate>true</rd:ReportTemplate>
<Page>
</Page>
</Report>
I came to this solution, after installing all suggested tools/templates, still could not view the option/button to add a rdlc tool.
Using this technique you can now open/edit the file in the reportViewer Designer inside Visual Studio 2019
PS: This solution applies to .net 5 projects, and .net core 3.1 projects also, has chance to work on .net core 2.x project (didn't test this last).