Most SPA delivery issues are not frontend bugs. They are server routing mismatches.
The homepage works, client-side navigation works, and then someone refreshes a deep link in production and gets a server-side 404. It happens all the time because backend and frontend route ownership was never made explicit.
Fiber v3 makes this easy to solve once you set the pattern correctly.
Static delivery is one of those topics that seems boring until it breaks.
A frontend deploy goes out, cache headers are wrong, the browser serves stale files, and suddenly support channels fill with "I still see the old UI" messages. Or worse: your container image uses a different working directory than local dev, and assets that worked locally return 404 in production.
Fiber v3 gives you a very capable static middleware surface. The trick is not only to use it, but to use it with clear policy.