When I brought up useless cards before, somebody corrected me saying at level 70 it was not the case. I am not massively familiar with SB AST, so maybe somebody else can do a better explanation. But your cards aren't just used for the boost they give you, eg The Bole can be royal roaded into a potency boost.

Heck even then, I think the pre existing system could have been kept if the only change they made to the system was Lord/Lady, if you cannot use The Bole for whatever reason, Lady it.