This pattern expresses that something continues to worsen or increase without stopping. It carries a sense of helplessness or resignation. You use it when you feel that a bad trend is just getting worse and there's no end in sight.

It is formed with the dictionary form of a verb followed by ばかりだ. The verb is usually intransitive and expresses negative change, such as 悪くなる, 増える, 減る, 離れる, etc. The meaning is often translated as 'just keeps getting' or 'only continues to'.

You'll hear this in spoken Japanese, but it's also used in writing and news reports. It is not rude, but it does express a negative outlook, so use it when you really feel that way.