- API calls necessary to build the page happen in the data center instead of the public internet, so they're much faster. You can use a database query instead of an HTTP API call if you really want to. That results in a huge speed gain for a lot of sites. It also reduces the complexity of the page - devs don't need to build logic to wait for things. The page just doesn't render until it has the data it needs.
- You don't send the user code they don't need yet. If someone is viewing a page that doesn't have a widget, but you send them the code for the widget because you've bundled everything the site needs into one JS file, you've wasted the users time and bandwidth. SSR is a very easy way to solve that problem.
I'm of the opinion that SSR is a better alternative to a bad SPA, but marginally worse than a good SPA, so for most teams it's a good approach because building a good SPA is hard. If people want to use SSR and that results in me not seeing 4MB homepages any more that can only be considered a win.
There are two main advantages of SSR;
- API calls necessary to build the page happen in the data center instead of the public internet, so they're much faster. You can use a database query instead of an HTTP API call if you really want to. That results in a huge speed gain for a lot of sites. It also reduces the complexity of the page - devs don't need to build logic to wait for things. The page just doesn't render until it has the data it needs.
- You don't send the user code they don't need yet. If someone is viewing a page that doesn't have a widget, but you send them the code for the widget because you've bundled everything the site needs into one JS file, you've wasted the users time and bandwidth. SSR is a very easy way to solve that problem.
I'm of the opinion that SSR is a better alternative to a bad SPA, but marginally worse than a good SPA, so for most teams it's a good approach because building a good SPA is hard. If people want to use SSR and that results in me not seeing 4MB homepages any more that can only be considered a win.