Comments on https://lichess.org/@/engot12/blog/the-longest-chess-opening/izlXnwCg
There are probably longer lines: Open Ruy Lopez, Sicilian Dragon, Sicilian Najdorf, Sicilian Sveshnikov...
arent some lines in the botvinnik slav known up to move 25/30?
Well, that's what i found with the opening tool on lichess.org