A good rule of thumb is: if your app can/could run offline-first like a desktop app, it's ok to make it a single-page application. They can be snappier and better than a multi-page browser app. Examples would be stuff like Photopea, Google Docs/Sheets, tldraw, etc.

This way, the biggest downsides (moving between pages & requiring an internet connection) are eliminated.

But if your app requires an internet connection and multiple pages, it's better to let the browser handle navigation in a fault-tolerant way.