The tables and chairs comparison is valid actually. Can you imagine holding a card game tournament that didn't have any tables and chairs? This isn't a joke btw, you really do need tables and chairs for a card game tournament. It's a basic necessity. Just like if you went to a fighting game tournament, you need electrical outlets, power cables, game consoles, televisions, and hdmi cables. It's the tournament organizer's responsibility to make sure the event has the basic things it needs. Often, tournament organizers ask players ahead of time if they can bring various materials and items to make it easier, which is fine.
And by the way, you pretty much are expected to bring a controller to a fighting game tournament. I mean yeah sometimes you can get a loaner, but it's standard practice to bring your own. Just as it's standard practice to bring your own life tracking device in MtG. Whether a tournament organizer provides chess clocks, or tells players to bring their own, or tells players to use digital ones on their phones is up to the tournament organizer and how they want to run it.
So the rule is yeah you need chess clocks because if you don't have them, one player can take really long which is unfair to the other player. This (predictably) happened when we first ran tournaments for Codex, and even giving "stern warnings" didn't really help the situation. Chess clocks are infeasible in MtG due to passing priority like 100 times per turn and microsteps, but it's entirely feasible in Codex. "But a player can't be expected to bring a chess clock" is not a reason that the official tournament guidelines should omit them.