And on 500MBit it’s two minutes, so doubling the bandwidth only saves one minute.

This is simply not true, of course it isn't entirely linear, but for big downloads you actually get pretty close to the full benefit of the speed, when the servers can handle it.
When the speed goes up, latency also goes down, making response times faster too.

Sounds a lot like your Fedora update is single threaded, which is a huge limitation. I start updates manually and monitor the whole process, and the whole process is finished in a couple of minutes for a big update. A single package can be literally less than 5 seconds for download, integrity check and installation. Firefox is among the most frequent single package updates, and that generally takes 5-6 seconds.