Is SSR still much better for seo?
Yes. There's a separate queue for sites that need js rendering and it eats much more into your crawl budget. Best way to avoid it imo is to use something like Rendertron, which is made and recommended by Google.
Rendertron is deprecated
Please note that this project is deprecated. Dynamic rendering is not a recommended approach and there are better approaches to rendering on the web.
Rendertron will not be actively maintained at this point.