and the MC has quite a few young girls with him but continues to go on about how he only likes older ladies

Ah, the times I argued on reddit about whether or not Death March was a harem. Especially when the anime was announced people over there just dismissed it as a harem show. Yes, he has a party of girls with him but there was never any ambiguity about him seeing them only as companions/daughter figures. He never tried to touch them or did lust after them in his inner monologues. But for the r/anime crowd, it was a harem when there were girls in the party and that was that.