I flew for Swift Aviation, owned by Jerry Moyes, the founder and majority share holder of Swift Trucking, the single largest trucking company in the world. He told me the single reason he didn't get into air freight/cargo is that he didn't want to step on the toes of Fedex and UPS, both of whom are HUGE clients of his.. The Barriers to entry are indeed VERY high.
The future for growth in jobs lies in ACMI and this is why ACMI pilots may need to re-focus their efforts from "Getting hired at UPS or Fedex" to getting their pay/QOL up close to par with the later.