> Riseup provides online communication tools for people and groups working on liberatory social change. We are a project to create democratic alternatives and practice self-determination by controlling our own secure means of communications.
This is what they claim on their homepage[1]. Tools built by people who believe in a certain philosophy for people working on "liberatory social change".
They try to operate and control their tools. They don't claim that they are "the-most-secure-email-provider".
They claim to work on what they call "Network Security"[2] (traffic encrypting and providing services outside of the tracking bubble), and define other fields of security ("Human Security", "Device Security", "Message Security"), that the user can improve himself by education. They provide means of education for this.
This is an alternative. Gmail is maybe more "secure", or maybe not, but don't claim these kind of social changes. Gmail is "free" and commercial. Riseup is not free and volunteer-run.
[2] https://riseup.net/en/security/#security-overview
edits: typos