If you implement it on the frontend you lose all the builtin navigation behavior that the browser gives you natively when loading pages. You instead get to buil

If you implement it on the frontend you lose all the builtin navigation behavior that the browser gives you natively when loading pages. You instead get to build all that behavior yourself in places where you think it should exist using your best judgment (things like deciding when to push to browser history state, for example, may be perceived as breaking the back button to many users if you haven't thought through your app's navigation hierarchy very carefully).