The reasons one would want to create their own engine likely won't be understood by many ITT as it goes deep into how "objects" are defined in memory and requires a study in programming access patterns. Just understand that UE4 does certain things one way, when there are entirely valid reasons to do things another way. It's a very in the weeds topic that, no disrespect, many on this board won't get.
Particularly for things like RPGs, going with alternative programming patterns is a very valid reason for rolling your own engine, as RPGs can have enormously complex microkernels embedded into them.
Particularly for things like RPGs, going with alternative programming patterns is a very valid reason for rolling your own engine, as RPGs can have enormously complex microkernels embedded into them.