I'd say Buchner had more going against him in his opening start than Carr does now.
Columbus at night, against the #2 team in the country, a team that was an injury and missed field goal away from winning it all, a star-studded defense, and while it may not be a rivalry, ND fans sure do hate Ohio State. He also had to find a way to keep pace with CJ Stroud and an insanely talented offense with guys like Jaxon Smith-Njigba, Marvin Harrison Jr and Emeka Egbuka.
Not to mention, Buchner had nowhere near the talent to work with. His top receivers were Styles, Salerno and Lenzy, compared to now with Greathouse, Fields and Faison. Plus a much better OL and running game (they were also without their top lineman as Patterson was injured).