What is test data for?
Developers, QA testers and designers constantly need realistic placeholder data: names to fill a table, addresses to test a checkout form, emails to try a sign-up flow. Typing it by hand is slow and unrealistic, so a generator saves time and surfaces edge cases.
When a test needs a working inbox, pair this with a temporary email address: generate a disposable address, use it to receive the verification code, and keep your real inbox out of your test runs.