What will keep live auctions alive are two things. One the event and entertainment value. Many now are events people plan on going too for a fun weekend. Be it automotive it even tractors.
The other deals is there are people like me that really resist buying a vehicle sight unseen. This often results in major issues or a very unhappy owner. Some cars are well documented many are not. I generally want to look and see just what I am buying.
But online auctions are going to grow as many people in todays market want to buy now not when they find the right car. Some get lucky and get a good car some not do much.
Also if you are selling on line is often cheaper and faster than live auctions if you have a car that is not especially rare.