If you're optimizing for time to first render, or time to visually complete, then you need to render the page using as little logic as possible - sending an empty skeleton that then gets hydrated with user data over APIs is fastest for a user's perception of loading speed.
If you want to speed up time to first input or time to interactive you need to actually build a working page using user data, and that's often fastest on the backend because you reduce network calls which are the slowest bit. I'd argue most users actually prefer that, but it depends on the app. Something like a CRUD SAAS app is probably best rendered server side, but something like Figma is best off sending a much more static page and then fetching the user's design data from the frontend.
The idea that there's one solution that will work for everything is wrong, mainly because what you optimise for is a subjective choice.
And that's before you even get to Dev experience, team topology, Conway's law, etc that all have huge impacts on tech choices.