I'm a big fan of CSR, and I don't think it's as bad as some detractors claim it is (or was), however, Server-Side Rendering will always always always be ideal. You simply can't beat it, no matter how good Client-Side Rendering gets over time!
I just feel like there's no competition: CSR will never supplant SSR, though for some cases just using CSR is good enough™ and it's okay.