Fusion would be an attractive source of electricity. Hydrogen fuel is plentiful, and the product, helium, is not radioactive. But no one has yet built a fusion power station that is practical and economic.
The main problem is the conditions needed. The fuel must be heated to millions of degrees, hotter than the core of the Sun, and held at a high pressure. At this temperature the fuel is a hot gas of charged particles called a plasma. No material container can touch it without melting, and the plasma would cool if it touched the walls. So it has to be held away from the walls by strong magnetic fields. Keeping the plasma stable and hot enough for fusion to continue is very difficult.
The second problem is energy and cost. Heating the fuel and running the magnets takes a lot of energy. A power station is only useful if it gives out more energy than is put in, and it must do this reliably and cheaply. The machines are very large and expensive, and so far experiments have only produced fusion for a short time. Until the conditions can be kept going cheaply, fusion is not an economic way to generate electricity.