There is another factor, at least for season-ending rivalries like The Game that has diminished them, IMHO.
What I am referring to here is the time before your next game. Until the mid-1970's the BigTen had the RoseBowl only rule which meant that only one team from our league went to a bowl. Consequently, The Game was the last game for at least one of the participants for about nine months. Even if one of the two teams did go to the RoseBowl, The Game was still their last game for about six weeks.
Even once the RoseBowl only rule was dropped and the Buckeyes and Wolverines were both generally playing in bowls every year, there was still a roughly six week gap between The Game and the next game.
Now the CG is seven days after The Game so for a team that is in the CG, The Game has the same gap as a normal regular season game. Then, with the expanded playoff, even though neither team was in the CG (due to the result), Ohio State's next game was the opening round CFP game against Tennessee three weeks after The Game.
So the time to celebrate a win or stew over a loss before moving on to the next game has progressively dropped from almost a year in the early 1970's to roughly six weeks from then until the CCG to now three weeks or even just one week.
Are Ohio State fans still stewing over the loss, sorta but not really. The fanbase took this loss particularly hard which contributed to the lower than normal home attendance that allowed Tennessee fans to grab a substantial portion of the tickets for the first round CFP game. Once that game got to 21-0, I think most Ohio State fans moved on to thinking about Oregon and then Texas and now Notre Dame. If this were 1972 instead of 2024/5 the Ohio State fanbase would only be a little less than two out of nine months into stewing over the loss in The Game. Instead, our team has played three games since then and is about to play another one . . . for a National Championship.
