I am totally against “bumping” people against their will, especially when it typically is so an employee can dead head a ride.
The inconvenience when in effect you have paid for a contract for transportation is significant. Ailrines need to compensate appropriately if they think it’s cost effective to overbook - pay those more than one free ticket, I say give them two tickets to anywhere domestically and a $500 hotel voucher. That will ususally work as an incentive.
If not, then hire a lear jet to fly the overbooked passengers.
What you propose would be much more cost effective for United than the lawsuits coming over this incident. Not only will the removed passenger sue, but some of the other passengers will also sue, due to the trauma they experienced. It will not turn out well for United AL.
Usually the flight vouchers they hand out are so restrictive that in the end, they aren’t worth it.