It's much more performant if you give yourself backdoors into the source code instead of standing up an entire database. You can, of course, stand up an entire database seeded with test data (as you would in rails). DB seeding is something many people do within Cypress in the plugins file. The tradeoff is always access to the backend + frontend codebase (if you maintain it and can easily add test-only hooks) vs if you have to test it as a blackbox. Blackbox is slower, more expensive, and more brittle... but you'll catch an additional layer of issues.