To review lead routing properly you need the configuration itself, not a screenshot of Setup: every assignment rule entry, every flow that touches the owner, the queues and the picklist values they test.
Who can export it
Salesforce only lets a user retrieve configuration if they could also deploy changes, so this is a job for an admin, with their own login.
What to export
AssignmentRules: Lead
Flow and FlowDefinition: all
Queue: all
CustomObject: Lead
GlobalValueSet: all
StandardValueSet: LeadSource, LeadStatus, IndustryThat is configuration only. No lead, contact or opportunity record is included. The free scan offers this list ready made as package.xml.
Option 1: nothing to install
At workbench.developerforce.com, log in, then Migration, Retrieve. Choose package.xml as the unpackaged manifest, press Next, then Retrieve, then Download ZIP File. Workbench is a long-standing community tool that Salesforce does not support.
Option 2: the Salesforce CLI
sf org login web --alias ourorg
sf project retrieve start --target-org ourorg --manifest package.xml --target-metadata-dir rf-exportIt saves a zip in rf-export.
Then read it
Walk each assignment rule entry in order, and each flow that sets the owner, looking for entries that can never match, entries hidden behind broader ones, and owners who have left. Or drop the zip on the free scan, which reads it in your browser and never uploads it.
Have it checked every night instead.
Routing Forensics connects as a read-only user and checks this, and the rest of your routing, against your real leads. Register interest and you will be first to get a free health report: what is leaking, where, and what it is worth.
Or check it now: the free scan finds entries that can never match, entries hidden behind broader ones and hard-coded owner Ids in your Salesforce export, in your browser, and nothing is uploaded.