If you can’t leave, your membership is forced. What is it you fail to understand?
I understand perfectly well what sharia is. It it a medieval idiocy which forced people to submit to set of stupid rules.
There is compulsion in Islam. This is what keeps it alive, while it brainwashes its adherents do that they like you repeat phrases you learn without any critical thinking.
Your refusal to see compulsion in a way Islam treat apostasy demonstrate quite well what Islam does to mental abilities of believers.