Is 5GHz Wi-Fi faster than 2.4 GHz?

Is a frequency band of 5 GHz better than 2.4 GHz for the connection with a WLAN repeater?
The repeater is connected to my Google Stadia via LAN cable and would the connection become more stable if I connect the repeater to my router with 5 GHz Wi-Fi?

5 GHz has a lot more channels, I built such a WLAN card into the laptop, and the internet has been running on the laptop ever since. Before that, the 2.4 channels were often full

If the connection is strong enough, yes

Advantages of 5GHz: Greater bandwidth and more channels. This makes it faster. However, the range is less. Depending on the distance to the router, 2.4 GHz can again be an advantage.

Different demands are faster and more stable. If we assume a laboratory environment, 5GHz Wi-Fi is faster but 2.4GHz Wi-Fi has a greater range and stability with the same transmission power.

In the real case it depends on the environment. If many networks are in the 2.4GHz band but only a few are in the 5GHz band, the 5GHz band is faster and more stable. If both are occupied it depends on which channel you are less disturbed.

I would just do it with 5GHz and if that doesn't work at all you can try the 2.4GHz. But if you want a really stable connection for gaming, use a cable.

With 2.4 Ghz you have a higher range, with 5 Ghz, however, more bandwidth. Which is better depends on your own needs