Google Analytics (GA4) tells you what happened to your traffic. StoreVitals monitors the technical issues that cause traffic to drop before they show up in your analytics. Different timing, different signals.
Google Analytics and StoreVitals are complementary, not competing. GA4 answers 'what is happening with my traffic?' StoreVitals answers 'why might my traffic be at risk?' By the time a technical problem shows up in your GA4 data as a traffic drop, it's often been active for weeks. StoreVitals monitors the upstream causes — broken pages, missing meta tags, security issues — so you can fix problems before they become traffic crises. Every ecommerce store should use both.