The market would reach equilibrium. Fees would go up and discourage new miners. This wouldn't happen though until 10000 miners are already protecting the chain. At some point the entire Block space would always be filled up and some amount would be new miners and others would be regular transactions. You can create your transactions now while it is early and you can use them forever. They will never go away unless you spend them. Smart to take that real estate right now while it is easy.