I would not chase a perfect Lighthouse score while the offer on the page is weak. Performance matters because slow pages lose impatient buyers. Scores are a means, not a business strategy.
Start on money URLs
Product, pricing, booking, checkout.
Fix LCP, CLS, and blocking scripts there.
Ignore vanity on blog archives
Improve, do not obsess.
Pair with Search Console
Core Web Vitals in the field beat lab scores alone.
Do not game
Fake lazy loading tricks that hurt UX.
Strip content to win points.
Lighthouse is a free mechanic's diagnostic. Use it on pages that pay rent, then verify real users feel the difference.