Delta wings combine low supersonic drag, structural efficiency, internal fuel volume and space for semi-conformal and external stores. They're also resistant to stall and transonic wing drop.
The bad news is that high lift happens at high alpha with lots of drag, and you have less space for pitch and roll control. European engineers have mitigated these problems with double-deltas, canards and relaxed stability.
The US teen-series and the contemporary Russian fighters were designed with a heavy emphasis on transonic maneuver, before anyone was ready to attempt the degree of relaxed stability that's necessary to make a canard-delta do well in that regime. (Typhoon has been described as an airplane that would have natural pitch stability if you took the canard off.)
By the way, all the JSF designs were canard-deltas or deltas before the Navy got involved.