Additionally, I can find 6am flights, which means that I can be at 8am at the destination and have a full day ahead of me. By train the whole day will be dedicated to travel. Same on the return. Losing 2/3 days on a business trip is a big cost to pay.
Sometimes. But if I'm flying out to somewhere at 6am, the alternative is often that I'd just be spending the night in my own bed. Now, to be honest, I'm sometimes fine with heading down somewhere the day before and having a relaxing evening at my destination. But that may not be ideal for people with families and isn't really justified from a business standpoint.