It's important to note that not all English grammar checkers are created equal, and some may be more effective than others at identifying and correcting grammar mistakes. Additionally, the effectiveness of an English grammar checker may depend on the specific needs and goals of the user. Some users may find a grammar checker to be helpful in identifying and correcting basic grammar errors, while others may find that it is not as effective at catching more complex or nuanced errors.

It's also worth considering that the effectiveness of an English grammar checker may be influenced by the quality of the input it receives. For example, if a user inputs text that is already well-written and free of grammar errors, the grammar checker may not have much work to do. On the other hand, if the input text contains many grammar mistakes, the grammar checker may struggle to accurately identify and correct them all.

In summary, while some English grammar checkers may not be as effective as others, this does not necessarily mean that all grammar checkers are "terrible." It's important to carefully consider your specific needs and goals when selecting a grammar checker, and to use it in conjunction with other tools and resources to help improve your writing.