Now I think about it, I think every company I worked for booked all travel for employees, except in an emergency.
When I was traveling extensively, PSA was still flying. They used to sell booklets of 20 tickets. No reservation needed, just walk up to the counter, give them a ticket and they put you on the next flight. I flew a lot of Sacramento to Los Angeles and back, and if a flying was full, no big deal, they had flights leaving on the route every hour from 6 am to 11 pm. The bosses Administrative assist would just hand us a book of 20 tickets.