I just found GameStar Bf5 for 11 euro.
Should I buy it or not because of the free alternative Fortnite Apex etc.
BFV is worth buying, in my opinion, if your computer does it. I enjoy it very much and I'm Apex etc. A good alternative to play something different.
The alternatives mentioned are completely different directions. If you are concerned about battle royake, keep your hands off bf5.
Bf5 is more for more realistic multiplayer battles where it depends on team play and tactics.