Fischer used to show up late for his games.
Nowadays this is forbidden.
'6.7.1 The regulations of an event shall specify a default time in advance. If the default time is not specified, then it is zero. Any player who arrives at the chessboard after the default time shall lose the game unless the arbiter decides otherwise.'
https://handbook.fide.com/chapter/E012023
What do you think about magnus showing up late to his chess games sometimes? is this good behavior from a world champ or low class? what would you do if anything in this situation if magnus was making you wait because he was late?