The online travel booking industry was one of the hardest hit by the coronavirus pandemic, with some apps reporting more than 70 percent less traffic and bookings than 2019. It took two years for most online travel agencies, hotels, and airlines to see a return to form, although for some the levels of revenue and occupancy are still below 2019 figures. Booking Holdings and Expedia Group are the two juggernauts of the online travel booking industry, and account for about 60 percent of all trav...