I can spot a dead SOP in about thirty seconds. It is never subtle. Here are the mistakes that do the killing, in no particular order.
Opening with a dictionary definition or a famous quote. Readers groan out loud. They have seen it a thousand times. The childhood origin story is next. Nobody believes your passion for supply chain management started at age six, and pretending it did insults everyone. Then there is the resume in paragraph form. They have your CV. The SOP is for the story behind it, not the list.
Generic university praise is a quiet killer. Your world-renowned faculty and excellent facilities could describe fifty schools. Name the lab. Name the professor. Name the course. Vague direction is another one: "I want to explore many areas" reads as "I have no idea." Have an idea.
Blowing past the word limit signals you cannot follow instructions, which is a strange flex for a grad school application. Typos: one is human, five is careless. Performative hardship humblebrags make readers uncomfortable in the wrong way. Copying an SOP template library SaaS sample so closely that your essay matches three other applicants, that one actually happens. And ending with "thank you for your consideration." That is not a conclusion. End with where you are going.
Run every draft through a statement of purpose checker app free tier for the mechanical stuff, then get a human to judge the rest. If you need statement of purpose writing help or a proper SOP review service for that judgment call, get it before you submit, not after the rejections arrive.
And if you want the draft built around a specific university from the start, the tailoring packs at sopexpert.fyi handle that.