Two situations I have seen in FIDE-rated tournaments:
Both players making nonsense moves (mostly king moves) throughout the game. At around move 20, the arbiter stepped in and gave it a 0:0 score. [I guess they were going to agree to a draw at some point.] In this case, the arbiter didn't agree to the idea "if it's legal, then it's good".
Two juniors continued playing after reaching a K+R vs. K+R endgame, neither agreeing to a draw, nor claiming a draw by 50 move repetition [when it became possible]. They played on for hours in this situation delaying the next round of the tournament. (NB. In their defense, both had been instructed by their coaches not to offer nor accept draws under any circumstances.)
(Actually, a similar situation happened to me online once: my opponent kept playing a K+R vs. K+R endgame, and I was so disinterested my rook got skewered and they won the game. I felt that was rather unsporting, but I have to recognize that it actually worked.)