[WA]

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.

[synergy20]

This is a good point. Web platform is now doing both websites and GUIs cross-platform. If you need anything offline or desktop GUI alike across multiple OSes, SPA is your friend, if you just want to build a website, SPA might not be the best fit.

[j45]

Snappier is an outdated concept. HTML has lots of tools in it now.

SPA's are one thing, the complexity to create it is another.

[layer8]

You have to test a lot though, especially in contexts like gov.uk, since a significant number of users is still using older phones with browsers that aren’t updated anymore (like for example iOS 15 Safari).