Is this bacterial wilt?

The garden bed has a capsicum and 2 chilli plants. They have been sad looking for a couple of weeks now and I tried increased water and fertiliser but nothing is helping.

If it is bacterial wilt, my googling says the plants can’t be saved but now do I make the soil safe to plant new plants.

I had been suggested to plant legumes or beans after the chilli’s to help improve the soil. But I’m not sure if I still do that if bacterial wilt is in the soil.

Note: I’m in Darwin, NT.