Learning atmosphere: This directly determines whether you are interested or motivated to continue learning. A good learning atmosphere can greatly affect the people in it. Even those who don't want to study, it's hard to be unmoved by watching people around them study.
Institutional qualification: whether an institution is mature, experienced and formal determines the experience of people studying here. A high-quality platform can provide students with more than knowledge.
Institutional teacher: The teacher is always the best guide. If the teachers are all bad and lead the wrong way, even if you try harder, the horror will get farther and farther away from the finish line.
Curriculum: Don't underestimate the reasonable and scientific curriculum, which can help learners gradually establish some learning habits and ways. If it is only mechanical learning, the final result is often mechanical.
So, within your tolerance, don't always focus on the benefits. And really cheap English training is not safe to learn.