Why do people risk getting banned for bronchodilators?

I can “understand” why in performance horses a competitor might want to hide lameness with painkillers or anti-inflammatories, or sedatives or stimulants etc… but I’ve seen several times now trainers getting suspended or banned for bronchodilators, and if the horse doesn’t have heaves or other breathing conditions, what do they actually do? Does it make the horse able to work longer at faster gaits? I’m assuming the “benefit” is real because people keep doing it, but I’m curious what the point is?