It's all about entertaining the fans, marketing for automotive manufacturers
True facts, when I went to the Suzuka F1 race 20yrs ago with Honda as design engineer, everyone on the team needed a visitors visa
Occupation description on my visa was 'Entertainer'
Honda is the only automotive manufacturer that does or has done motorsport for fast tracking their young road car engineers learning/experience and because it's a difficult challenge
Marketing benefits have always come a long distant 2nd on Honda's priority list
Every other manufacturer goes racing for publicity and to increase sales