Developers. I ask you to solve the problem of Prague airport. Why does one runway work and the other does not? After all, in reality, both work. And probably many people are already asking you to fix this problem. I hope you will notice my message.
In reality both are technically used, but never simultaneously. The 06/24, which is the one used in the game, is the main one and is used most of the time. Only when it can’t be used (e.g. weather/winds or maintenance, which will actually happen this year for about 4 months - although not maintenance of the RWY itself but connecting TWYs and other infrastructure), the secondary 12/30 is used. The approach routes for the 12/30 lead over densely-populated areas of Prague and Kladno, so its use is also strictly regulated.
The way the airport works in the game is therefore actually true to real life. You can observe this on Flightradar, if you don’t believe me.
There are plans to build a parallel RWY 06R/24L, but that won’t happen earlier than in 2030s.
Luca is correct, they are never used together and the devs have categorically said many many times over the 5+ years this game has been in existence that it will never have both runways operating at the same time unless the new runway is built.