Universal Analytics is gone. GA4 is the standard. And despite having been compulsory for well over a year, most marketing teams are still using it as if it were UA with a different colour scheme.
The data model shift that changes everything
Universal Analytics was session-based. Everything was organised around a visit. GA4 is event-based. Every interaction - a page view, a scroll, a click, a form submission - is an event.
This matters because the event-based model is far better at tracking the non-linear, cross-device journeys that most customers actually take. A user who researches on mobile, abandons, and converts three days later on desktop is far better represented in GA4 than it was in UA.
Three reports worth knowing
The Funnel Exploration report is the first place I go in any GA4 account. Unlike UA's funnel reports, it's flexible - you can define the steps yourself based on any combination of events and conditions. Used properly, it surfaces exactly where users drop off in commercial journeys.
The Path Exploration report shows what users actually do on a site in sequence - which pages they visit, in which order, and where they leave. Particularly useful for identifying unexpected journeys that convert at higher rates than the planned ones.
The Advertising workspace - specifically the conversion paths report - shows the sequence of channel touchpoints that precede conversions. If you're making budget decisions based on last-click data, this report will often change your view of which channels deserve more investment.
The setup work that makes it reliable
None of this is useful if the event tracking is incomplete. The most common GA4 problem isn't incorrect report reading - it's incorrect data collection. Before trusting GA4 for commercial decisions, verify the underlying event data using GTM's preview mode and GA4's DebugView.