Web Vitals is a set of ±10 metrics curated by an internal Google team that lets you evaluate and numerically quantify the performance of a web page. The value of this particular set of metrics and the reason it’s popular with frontend developers is that all those metrics have a direct impact on the user experience of the page users.
What’s not to like: just make some test data, pass it to a function or a component, and compare the output to the snapshot. Boom, the test is ready, and there’s no “testing fatigue”, where I get a bit tired and absentminded after writing a bunch of tests in a row.
But are there any disadvantages to this type of testing? They can’t be a panacea after all.