Much as I'd like to see Trump-lawfare-operative who broke laws imprisoned, their having Presidential pardons would be a thick layer of tarnish on their reputations. And since these proposed "preemptive pardons" would be given more widely than simply those who had broken laws, the tarnish would also be more widespread. Not a great consolation prize, but a little better than nothing.
This is hypothetical, of course. Whether LIEden would do this, make it the last and most prominent aspect of his Presidential legacy, he might recoil from that. Or ask for more ice cream.