It is not certain that anyone's profits will eventually be eliminated by competition; it is in the nature of competition that you have a chance of winning, as well as a chance of losing. And lots of people enjoy competition.
The fur trade was the first profitable industry for the French in Canada.
Ranchers made the western cattle industry profitable. They did this by selling and raising cattle for food and agricultural purposes.
Weapons/military sales
no
Competition helps to keep the quality high and prices down. If competition decreases, the quality can go down and the prices can go up in that industry.
Cable TV Industry Yes, cable TV has been a profitable industry. Its margins are now being cut by increased competition from satellite TV companies like dish and DirecTV along with the rise of streaming services like Netflix and Hulu.
The fur trade was the first profitable industry for the French in Canada.
farming
A monopoly is an industry or business having no competition.
farming
mining
Ranchers made the western cattle industry profitable. They did this by selling and raising cattle for food and agricultural purposes.
Baseload plants allow competition in the power industry.
Andrew Carnegie used horizontal integration. He bought out his competition through this technique making his business more profitable.
Oil.
Competition for land, trade, and industry increased
Weapons/military sales