Rider does not have a community edition unlike IDEA. It was created due to a combined threat of VS Code and Roslyn and is the reason ReSharper is almost neglected these days.
ReSharper isn't a heavy focus because it's not worth it anymore. To get the same performance as other tools they'd need to throw out a ton of work and rewrite it for Roslyn. With Rider, they get to continue to use their existing ReSharper codebase to power it.
They don't forget to charge same (even increased) fee for minimal updates, though.