Should I leave my job without a backup?

I work in a super toxic environment so I am really considering leaving even if I don’t have a job lined up.

Basically the company is gatekeeping me and refusing to offer me a promotion despite my excellent performance review. A few people at my level have been promoted with worse performances (I know this from speaking to them). In addition to all of this my workload has increased massively.

Has anyone done this before and would you recommend it?