I'm afraid it is market forces. Many newspapers have come and gone. If the newspaper isn't popular enough then it closes.
However, rhe people who seem to be gloating at its demise seem to have misunderstood the newspaper. It was not, and never purported to be unbiased. It aimed at Governments, Labour as well as Conservative.
It was Independent of owners who were Lords or Labour party connected. However, when it was sold to a Russian oligarch, notions of non interfering owners with a political agenda became nonsense.
I thought it was a good product, but not enough other people did.