"unnecessary competition" is grammatically correct and can be used in written English.
You can use it to refer to any competition that is not needed or serves no useful purpose. Example: The company's aggressive marketing tactics created unnecessary competition among its own products, leading to confusion among consumers.
The unnecessary competition narrows education and turbocharges the stress for 10 and 11 year-olds.
Thus began the "Great Game", an entirely unnecessary competition for Afghanistan between Russia and Britain, conjured up by armchair polemicists in London.The war began promisingly.
And he cautioned that "there will need to be greater safeguards to ensure that vital services are not destabilized by unnecessary competition".
Recipes and other magazine-type features that infuriate its news rivals are often mentioned as an unnecessary competition against the likes of Mail Online or the Guardian.
The NUT unveiled a number of case studies in which free schools were opening in areas where there were already surplus places or where their establishment would create surplus places, leading to what the NUT said was unnecessary competition.
The artificially created desires lead to unnecessary competition and strife.
First, it would set up a regulator for private couriers, which they say is unnecessary since competition and a plethora of laws keep them in line.
But today, Icann said it had realized that VeriSign's hold on the market had weakened more quickly than expected, making a spinoff to create competition unnecessary.
Regulation 10 makes whatever Monitor judges to be an "unnecessary" restriction of competition, illegal, effectively closing down the current option of one state body (a commissioning group) making a new arrangement without competition with another (an NHS trust).
In the end, a report accompanying the House bill does not ask the agency to restrict the scope of the database, but instead "urges NIH to work with private sector providers to avoid unnecessary duplication and competition with private sector chemical databases".
The two Republicans on the commission also oppose the rules strongly — as do Republicans in Congress — because they consider them unnecessary to protect competition online, and because innovation on the Internet has thrived in the absence of government involvement.
