The alternative always arrives looking like an escape. Open source instead of proprietary. Mastodon instead of Twitter. A worker cooperative instead of a corporation. A credit union instead of a bank. And sometimes these are real differences. Sometimes they are the same structure wearing different fonts.
The tell is who controls the infrastructure underneath. Mastodon is federated until your instance admin burns out and sells the server. Open source is community-governed until a foundation forms, takes VC money, and hires a product team. The cooperative is horizontal until it scales past the point where everyone knows everyone, and then the informal hierarchy that was always there gets job titles.
Co-optation is not a conspiracy. It is a pressure gradient. Any structure that works gets noticed by capital, and capital has more patience than movements do. It can wait. It can fund the conference, sponsor the project, hire the core contributors. By the time the politics shift, the infrastructure is already owned by someone who did not build it.
The exit is still worth taking. A credit union is better than a bank even if it is not a revolution. Mastodon is better than Twitter even if it is not an escape. Fedora is better than Windows even if Red Hat answers to IBM. The point is not to find a pure alternative, because there is no such thing. The point is to understand what you actually traded and what you did not, so you are not surprised when the new thing starts behaving like the old thing. It usually does. Plan for it.