If you do that in a big sport where people can easily detect if you intentionally did such mistakes you'll be questionable, fixed games mostly happened with small / unpopular competitions, money can manipulate those on the lower leagues, while with big leagues and popular sports, medias are everywhere a mistake will surely be eyed for questioning and players/teams are all liable if proven.
Most of those professional stars are fully aware of the consequences in case involvement with kind of illegal things has been proven.,
A tough call for them as they will risk their fame and reliability just for the sake of some money, unless it's worth taking everything for granted.
Usually unpopular sports like local sports draws a little attention than those in big sports and most probably fixed matches will be likely real in this category of sports. Like what you've mentioned mate big and known sports have the media and people's eyeing the anticipated event so in most cases those players in this type of game are a well skilled player so definitely it would be hard to fixed a match of this type of game. However, either fixed matches happen on a small spots event or in a big event it shouldn't be tolerated because the probable victims are those bettor who don't have any idea about it.