Go / baduk / weiqi is also amazing from the point of view of how much stamina the players have to have.
See, for example, https://senseis.xmp.net/?LongestTimeSpentThinkingAboutAMove
See, for example, https://senseis.xmp.net/?LongestTimeSpentThinkingAboutAMove
I watched a lot of Shogi match, and that just make 3.15 hours allotted in WCC looks low.
(The 8-9 hour match is a 2-day match. At specified time on the first day player do sealed move, to be reveal at the beginning of a match the next day.)