The rouge paradox

The concept of permadeath, that is having your character die permanently and removed from the game upon death, would be impossible to insert in to your average jrpg like say Final Fantasy VII. Your characters require such an enormous time investment that losing them after dozens of hours of playtime would be unacceptable. Therefore games with permadeath like Mystery Dungeon have to be rather short affairs. They can still offer significant length due to high difficulty but a skilled player needs to be able to plough through them in one sitting. This is the only way permadeath can be balanced with the character building aspect of rpgs.

Rougelikes such as Mystery Dungeon solves this by having your character level up very fast, making the prospect of doing it all over again less daunting. Console based rougelikes do however usually offer you the ability of upgrading once equipment and saving it in some sort of storage between deaths. The later areas then naturally start to more or less require this high level equipment that has been gathered and improved on under multiple play throughs. The problem is that we are then faced with the unacceptable combination of permadeath and significant time investment in once equipment, equipment which will be lost if carried by the player upon death.
This is why most Rougelikes are broken unless they offer some sort of ability to safeguard this valuable loot. But to offer such a thing would sabotage the high risk gameplay, which makes the genre so appealing in the first place.