That exists and it's called ocean freight. Air freight is where you pay a premium to get a small amount of stuff there NOW. Ocean freight is what you use when you need 15 shipping containers of stuff there in a couple of weeks.
Whether there is any market for an "in between" mode is an open question, and it's the business case of these airships for better or worse.
Whether there is any market for an "in between" mode is an open question, and it's the business case of these airships for better or worse.