Dtg has previously stated that ue5 requires everything to be rebuilt from the ground up. Remember ue4 to ue4 was massive headache that took a bunch of time and effort. 4 to 5 would be even more without much benefit. Ue5 is pointless if it's not done properly
This. The biggest benefit UE5 has is Lumen which will KILL lower end devices and make optimisation even worse - No need to change UE 4.26 - UE5. The cost-time ratio litterally isn't worth it given it will kill a decent chunk of playerbase.
