Why doesn't NASA transfer its energy from Mars to Io, Enceladus, Uranus and Neptune?

Jupiter and Saturn are too far away, the mission cycle is too long, and the launch window is too long.

The window period of Mars is about two years, while Jupiter and Saturn are much longer.

Moreover, even if it is directly launched to Jupiter through the window, it will consume a lot of fuel. If it is to save fuel, it will take more time.