Given the fact that these are mostly show grilling for publicity (and it negatively affects the company) wouldn't just make sense for the board to reccomend the CEO not to show up?

Contempt of congress is like a 3 month sentence some 2-3 years into the future. Who knows who the CEO is gonna be by then and if it's still the same person it could be seen as an opportuinity to pass the baton or put a temporary CEO in place instead.

Even the CEOs themselves could think about it, 3 months sentence in 2027 maybe better than 3 hours grilling sitting there having to take it without any chance to answer back when attacked