There are lots of sport types that have been marked as “NOT CURRENTLY PLANNED” under Ideas:
These have thousands of votes and I believe some of these are low hanging fruits. Not talking about exotic sports like diving chess or ulak tartysh, but rather something very popular across the globe, like volleyball, basketball, rugby (we already have a soccer) or padel (there are racquet sports already).
Would be also nice to reconsider some extra fancy sport types in order to make bigger fun factor for the site, like horse riding, scuba diving, martial arts, or even free flying. These sports are side-sports (or even main) to many and would significantly raise the social / fun factor of the site. You may also skip the calculations (like kcal burned) if it’s too difficult, just make an icon and dropdown option :)