I think a modern cartel does not need fully block competition to be successful merely slow down competitors and put up lots of road blocks such that new entrant

I think a modern cartel does not need fully block competition to be successful merely slow down competitors and put up lots of road blocks such that new entrants can’t compete on cost. Many industries in the USA are quasi cartels, 2-5 companies own most of the market and competition is quashed by it being very difficult to break in. The airlines are a cartel but occasionally you see a new airline or there is a private equity attempt to cartel the vet business dispite the fact that some new independent vets can enter the market.