His conceding that Saturday or shortly thereafter could have made a tremendous turnaround in today's overall situation. Definitely a Republican Senate and Democratic House . And likely 1/6 in a much less toxic atmosphere (if at all).
1/6 occurred largely because Trump himself refused to admit defeat. If he did, there would only be a few disgruntled voters who'd still think he won (most Republicans who are in the Sedition Caucus wouldn't be in it), so there wouldn't be enough momentum for anything beyond a pathetic protest that gets quashed quickly.