The English Channel was too much of an obstacle to invade Britain; Germany never had the surface naval power to mount a credible invasion of the USA. Which is not to say that it could not have been developed, but logistics argue strongly against it. One of the primary reasons to invade the USSR in 1941 was to acquire the oil fields around the Black Sea. In fact, that might have been achieved had the political desire to take over Stalingrad and Moscow not been equally compelling to Hitler. Had Hitler taken the oil, then there’s no telling how the rest of the war might have played out.