Why can't WeChat have the function of "two-way mutual deletion" like QQ?

QQ mutual deletion is also an old story. The chat content and transfer records of both parties are very valuable information. Chat records can be used as evidence in judicial proceedings, and also have various levels of collection value, such as sweet talk between lovers, experience exchange between teachers and students, and bits and pieces between family members. If one party deletes friends, it will delete all the information left at the platform level, but this party has no right to delete the other party. Early QQ did have this function, but from the current point of view, this function is too mindless and willful. Nowadays, deleting friends or even hacking friends on WeChat and QQ is enough to solve most isolation needs. The so-called two-way delete each other's tweets dialog box is gone, as if nothing had happened. If you transfer your account to the liar, you won't ask this question again.