Rather than spefically cinemas, my opinion is that it is emblematic/a symptom of the state of hollywood as a whole. Cinemas and hollywood is a true symbiotic relationship. They cannot live without one another. At the same time, it also means that their fortunes are tied with one another. Cinemas get a cut of the ticket sales.
At the moment, hollywood is suffering from poor quality movies with ever ballooning budgets. Whether it is due to dei being the root cause, it is clear that not as many people like watching their movies as before. That's not to say that they no longer have hits, but their success rate is very low, only every once in a while they get something good like deadpool vs wolverine.
As such, if few want to watch those movies, then few will go to cinemas as well. It's not just sg, but all over the world including the US itself.
Of course, streaming like netflix is a main factor as well but ultimately hollywood itself is very weak at the moment.
