For a while SEO folks have kind of assumed there's a performance ranking part of the ranking algorithm or that one of the factors has to do with performance, usability and accessibility. There are strong signs that that is the exactly case because Google builds a lot of tools including Dev tools as part of the chrome web browser for you to see a lot of these scores on those metrics.
It is especially meant for developers to improve things for your website so that Google has an easier time accessing your content which they want to do. They want good content that is how they evaluate and rank to search users. So, we're all on the same page in this industry with the idea that the Core Web Vitals is something Google has determined recently will become a part of your ranking factor.
If you think of all the things that Google can measure in terms of performance, accessibility, SEO, best practices, problems, errors or anything else like that, Dev tools can present that information to you. Imagine the complexity of all that information and they just go you know what that's too complex let's bubble up scores to some peaks and figure out might make good sense for measuring user experience using these peak scores.
They've also come up with these nicknames like cumulative layout shift and first input delay, so you have all of these kinds of things that are sort of like a goal of several metrics underneath so that those metrics underneath calculate up to that goal and things that can get in the way of something like first input delay for example, are render blocking resource downloads or scripts that take a long time to evaluate.
If a script takes two seconds to evaluate that can slow down the availability of what that script does animating your page which can include things like clicks on buttons. For example, if you have ever loaded a page and clicked a button that you know is supposed to submit something and it doesn't submit that thing and then a few seconds later you click it and it does that is considered a first input delay. These Core Web Vitals measure how long it takes for components of a page to react to some user input and many other factors that they determine is part of the quality of a web page and they want to send users to high quality pages so you want good scores on these Core Web Vitals.