Why is some Unemployment okay, but Lots of Unemployment Bad?

-Some Unemployment, or really Any, means the Economy is not making use of its Resources Effectively. But it also keeps the Wage Rate Down -If Everyone had a Job and an Employer wanted to Hire a Worker, it would be Expensive -Unemployment becomes Serious and Determinantal when its Long Term and is too High -If the Unemployment Benefit is too High (JSA) then People may Actively not Seek for Work and Claim Benefits than Working for a Low Wage. This is an Unemployment Trap