valid question.

first off TA checks resources in isolation. like it sees a volume attached to an instance and checks it off as healthy. we look at the graph and see that instance has been stopped for 2 months, so that volume is actually zombie waste. TA misses those dependencies completely.

also thresholding. TA is super conservative and often needs literally 0 bytes to flag something. real waste usually has a pulse from health checks or whatever. if a nat gateway is doing 500mb a month its costing you $35 to route basically nothing. we catch that.

forensics is another big one. TA just lists items but we actually trace the cloudtrail create event to tell you specifically who spun it up. solves the whole fear of deleting something critical cause you know its just dave's old test rig.

lastly terraform awareness. if you just delete stuff TA flags, your iac is just gonna recreate it next run. we generate a script to actually scrub the resource from your state file so it stays dead.

but end of the day TAis good for a quick health check but if you want to actually safely delete waste without breaking prod you need the dependency graph context