... or perhaps they prioritize ensuring their consultants feel like they're being looked after - replacing them when they find another job is very expensive.
What part of my comment suggests consultants aren't "looked after?" The idea that the consultants' personal time is so low on the scale of priorities that the company prefers to pay 3x or 4x for plane tickets to ensure they are available to spend extra time with clients, rather than their families, suggests that the company is specifically NOT looking after the consultants' well-being.
That the consultants' personal time is high on the scale is why they pay for the flex-fare tickets. So you miss an 8pm flight for one reason or another - it happens, so "don't miss the flight" isn't a valid retort.
Do I feel better taken care of if I can just take the following morning's flight at no additional cost or hassle, or if I now need to contact someone at Amex Global Business Travel, have them try to get me on a flight, have another expense, potentially not be able to get on the next flight or the one after that, etc.
The company can start with heavily-discounted restricted tickets and eat them when a consultant needs to extend the trip. Today it's even easier because airlines have eliminated change fees - so essentially any ticket can be canceled and those funds credited to a future flight. It's all still "no cost or hassle" to the consultant since they aren't paying for the flights to begin with.
Yeah, replace consultants with clients in that comment and you’ll have the right of it.