Yes, it is kind of like locking up a murderer after the victim is dead. It doesn't prevent the original murder, but neither does it make it valid or does it justify anyone turning a blind eye to the fact that it happened. It also prevents the murderer from continuing to get away with more murder.
I say we identify the crime and punish those who perpetrated it - and let our wonderful elected representatives (or the ones left standing) sort out the mess created by all the unconsitutional actions. Isn't that a lovely thought? Biden (ugh) could always pardon the guy and repeat his actions to validate them (double ugh). But it would surely serve as a wake-up call for the people and serve notice that we aren't as likely to be duped in the future.