Is shuffling aimlessly for hundreds of moves permissible? As I write this, game 73 of the TCEC Season 18 superfinal has just ended. What was most &quot;interesting&quot; about this game is the sheer amount of shuffling both sides did: starting from around move 30 to move 200+, effectively nothing happened with Leela pushing a pawn only to avoid 50-move draws. It had three such moves to reset the 50-move counter, which naturally led to 150+ moves of shuffling. On move 220, Leela finally played 220. e4, which led to some trades and a more equal-ish position, but this also reset the 50-move counter and the shuffling started anew. The game went past move 300 with opposite color bishops on the board, enough for humans to say it's a clear draw, but Leela still saw a 40% chance for White to win, which led to more shuffling. Finally, on move 357 and faced with yet another 50-move draw, Leela's eval dropped and the game was adjudicated as drawn.
(This description makes it sound like it's Leela's fault the shuffling happened, but in fairness, Stockfish also saw a substantial White advantage for much of the game.)
This kind of scenario happens pretty often in computer chess, but I'm wondering what would've happened if this were a human game. Can the player with Black claim that White is being unsporting by shuffling and refusing to accept a draw? Are arbiters permitted to adjudicate if one player isn't making an active attempt to win the game, but seems to be merely prolonging it?
Can the player with Black claim that White is being unsporting by
shuffling and refusing to accept a draw?

No. White may be quite legitimately trying to win on time. In blitz this is always allowed. In longer formats it depends on the format.

Are arbiters permitted to adjudicate if one player isn't making an
active attempt to win the game, but seems to be merely prolonging it?

Only if there is no increment and the other player is down to less than 2 minutes on the clock. This is dealt with in the section called &quot;Guidelines III. Games without increment including Quickplay Finishes&quot; of the FIDE Laws of Chess and applies only if this was announced beforehand.

Guidelines III. Games without increment including Quickplay Finishes
III.1 A ‘quickplay finish’ is the phase of a game when all the
remaining moves must be completed in a finite time.
III.2.1 The Guidelines below concerning the final period of the game
including Quickplay Finishes, shall only be used at an event if their
use has been announced beforehand.
III.2.2 These Guidelines shall apply only to standard chess and rapid
chess games without increment and not to blitz games.
...
III.4 If the player having the move has less than two minutes left on
his clock, he may request that an increment extra five seconds be
introduced for both players. This constitutes the offer of a draw. If
the offer refused, and the arbiter agrees to the request, the clocks
shall then be set with the extra time; the opponent shall be awarded
two extra minutes and the game shall continue.
III.5 If Article III.4 does not apply and the player having the move
has less than two minutes left on his clock, he may claim a draw
before his flag falls. He shall summon the arbiter and may stop the
chessclock (see Article 6.12.2). He may claim on the basis that his
opponent cannot win by normal means, and/or that his opponent has been
making no effort to win by normal means:
III.5.1 If the arbiter agrees that the opponent cannot win by normal
means, or that the opponent has been making no effort to win the game
by normal means, he shall declare the game drawn. Otherwise he shall
postpone his decision or reject the claim.
III.5.2 If the arbiter postpones his decision, the opponent may be
awarded two extra minutes and the game shall continue, if possible, in
the presence of an arbiter. The arbiter shall declare the final result
later in the game or as soon as possible after the flag of either
player has fallen. He shall declare the game drawn if he agrees that
the opponent of the player whose flag has fallen cannot win by normal
means, or that he was not making sufficient attempts to win by normal
means.