I've worked on a number of these projects where clients were chasing Lighthouse scores without any actual measure of effort, reward, or impact.

Google Analytics offers many site speed metrics that are tied to real-world visits and can be correlated with other metrics, behaviors, and conversions on the site itself. These numbers also give you visibility on the entire site and not just a single page that you've run through the Lighthouse tool.

I don't want to discourage people from making the web faster but Lighthouse scores are about as helpful as domain authority and Alexa rank when you can take a detailed look at your users through Google Analytics and get more granular performance analysis from WebPageTest.org (which also provides Lighthouse scores, can be run privately, simulates various devices and locations, and much more).