How the Lighthouse fallback content audit fails
Each PWA audit is weighted equally in the Lighthouse PWA Score, except for three manual audits: Site works cross-browser, Page transitions don't feel like they block on the network, and Each page has a URL. Learn more in the Lighthouse Scoring Guide.
Progressive enhancement is a large and contentious topic. One camp says that, in order to adhere to the strategy of progressive enhancement, pages should be layered so that basic content and page functionality only require HTML. See Smashing Magazine's Progressive Enhancement: What It Is, And How To Use It for an example of this approach.
Another camp believes that this strict approach is unfeasible or unnecessary
for many modern, large-scale web applications and suggests using inline
critical-path CSS in the document
<head> for absolutely critical page styles.
better than a blank page because the blank page leaves users uncertain
about whether there's a problem with the page, their browsers, or their