Depends on what you build. I find a REST server + client side rendered frontend quite simpler to grok than a server side rendered page. Mostly because the separation between UI and data is really clear and all of the CLI interfacing comes free as well. There is certainly a way to split this well with SSR, but it's also easier to fall into the trap of tightly coupling the parts.

Sure, but you can just as easily fall into the trap of massively over-engineering your client-side rendering because you just grab packages off the shelf for every little thing instead of going "it's a little bit more work, but there is no reason to any of this when the browser already does this", like ending up with a 100kb bundle for what is effectively just a standard form that would work better, with less code, if it just used a normal form with built-in validation for almost everything, with the final acceptance/rejection determined by the api endpoint.

It really depends on which SSR approach we're comparing to which client-rendering approach, and who you're optimizing for.