Playwright (an open-source framework that drives a real browser through your product's flows), Cypress, Appium, Detox, k6 and their hosted cousins are tools. They execute what someone wrote. A managed QA service is the someone.
What a tool gives you
Execution, parallelism, reporting, sometimes recording and AI-assisted authoring. If your team has an engineer who owns the suite, decides what to cover, reads every red run and maintains selectors when the UI changes, a tool is all you need. Many teams with a QA engineer or a strong platform engineer are in this position and should stay there.
What a service adds
Four things that a tool does not do:
Deciding what to test. The checklist is a published answer to that question for AI-assisted codebases, with 53 items and pass criteria. A tool does not know that a new table needs a two-user test (sign in as one user, create a row, then try to read or change it as another user; pass is nothing comes back).
Writing and maintaining the suite. Someone has to grow coverage from zero to the plan limit and keep it green. On Growth that is 80 critical flows (a path a user takes that costs money or trust if it breaks: sign-up, checkout, invite, export) by month 2, maintained by us, in your repository.
Running what cannot be automated. Reading policy expressions, replaying auth flows out of order, denying permissions on a device, reading the credential inventory. Twenty of the 53 items are manual.
Signing a verdict (a one-word release result (pass, pass with findings, fail) with the findings and the checklist version behind it). A person reads the automated output and the manual results, names the build and the checklist version, and writes pass, pass with findings, or fail. A tool produces a dashboard; a verdict is a decision.
What we use
Playwright for web, Appium or Detox for mobile, k6 for performance smoke. All of it runs in your CI (the pipeline that builds and tests every change before it can be merged or deployed) and lives in your repository. We do not host a test runner you would lose access to. How it works has the details.
The honest boundary
A tool with an owner beats a service without a scope. A service with a published scope beats a tool nobody owns. If you have the owner, keep the tool. If you do not, the plans page shows what owning it costs, with limits.