SSRS has been completely neglected by the .NET team for years now.
For web applications, the only library available requires the ancient WebForms references, which aren't part of .NET Core or .NET 5/6/...; they're even a bit of a pain to use in an old MVC5 application.
After years of clamouring for MS to provide an updated library which can be used in MVC / .NET Core / .NET 5 etc, Microsoft recently responded by saying that we need to rewrite all SSRS reports in PowerBI, which requires a PowerBI Premium subscription.
Because paying for the Windows and SQL Server licenses isn't enough, obviously. 🤦♂️