Sure, some people will say "I can start my own business", but without capital how
do you do that? English teachers are nearly always almost broke half the time, or in
debt. A bank is not going to give some loser English teacher a loan without any
security.

To do that, you'd better have family members who can help, or go in together with somebody else. I've seen some laowai do it, but they've usually made a fair bit of money beforehand or at least had a property that they could sell, have a Chinese wife with rich parents (they'll often only be doing it because they want you to earn more money for her, mind) or had to really bust their balls with tutoring and part-time jobs with a future plan in mind. ESL teaching is a trap that can be hard to get out of. If you've only been doing it for 1 or 2 years, get out now whilst employers consider it to be novelty experience on your CV, rather than an ugly stain.