As I’ve mentioned elsewhere on the forums recently, in my opinion, the biggest weakness of UE4 is the netcode, if you’re working on anything beyond traditional shooters/action games.
My favorite genres are fighters, beat em ups, and racing games. Yet all 3 of those genres have issues with UE4’s built in netcode that haven’t been solved.
Fighters/beat em up’s are not favorable unless they use a rollback netcode implementation. There’s no packages or examples of rollback netcode in UE4, and GGPO has been open source yet to my knowledge nobody has been able to get it successfully integrated in to UE4. Several developers have expressed problems getting rollback netcode working in to UE4 because of issues with UE4 performing deterministic, and/or getting rollback working properly. With some of them choosing over UE4 for these reasons. For example, the developers of Killer Instinct and Power Rangers: BFTG.
Then with racing games, the UE4 vehicle systems using PhysX are not ideal. Bluemanphysics attempted to solve problem, but never performed well. Then FGear is now currently trying to solve it, and I hope they manage to soon (as I already purchased FGear), but they’ve expressed the difficulties due to PhysX. I’m not sure anyone has actually solved without switching to Bullet physics, but there’s no popular integrations of that in UE4.
If there was any marketplace packages solving either of these problems, it would be an instant buy for me. It just seems crazy that UE4 is so well featured overall, yet in the area of netcode, it’s very limited in terms of the styles of games you can make without having severe amounts of issues.