Generally, I find that the graphics are pretty but are often devoid of realism. That being said, the stories often told in the name of Solarpunk generally eschew capitalism as a default. The one book I read in the genre was explicitly post revolution, though it was a bit more anarchist than would be generally practical for the goals they were trying to accomplish. Certainly it's an interesting future imaginary, and it's better than yet another cyberpunk which by default reifies capitalism.

Is it impractical? yes. Is it worthless? Well, what's the value in imagining a world beyond capitalism? It may be a trap for liberals who want a better world but are blinded by ideology, but maybe it can break them away from capitalist realism to start seeing that a better world is possible.