He is not leading anything at the moment. His party won the most votes, but is far from having 50% + 1 seat. Merz depends on forming a coalition, and he basically alienated everyone.
I'm living in Germany. At the moment, the country is seeking stability after the FDP crashed the government, so a coalition with SPD seems to be very realistic. The far right party on rank 2 is hated by everyone and other coalitions required 3 parties...
Yeah the only option would be if SPD declares that they won't do a coalition if Merz becomes chancellor. But 1) that would require SPD to have some guts, which they don't have and 2) in that case the CDU would likely go for a minority government and work with AfD to push their cruel proposals.
So yeah, lile you say, realistically the GroKo is pretty much guaranteed.
Apparently I misinterpreted this statement by Scholz. I initially thought when I heard about it, he was speaking on behalf of the whole SPD and not just himself.
A minority government of Red-Green-Red (SPD, Grüne, Linke) would force the conservatives to either work productively with the other democratic parties or side with the fascists of the AFD. It would basically boil down to whether or not Merz will do again what he promised he wouldn't do (working with the AFD). Should he do that, I very much expect the CDU to "decapitate" itself by splitting from left to right: The MAGA people around Merz, Linnemann, Spahn and Dobrindt get ousted by the traditional conservatives.