How can I see the assets deployed on Statemint or Statemine parachains and read all their parameters and metadata? I would like to do that directly on Polkadot.js UI, is that possible?
Once you are in the Polkadot.js/apps UI, connect to Statemint network (Polkadot ecosystem), click on Network tab and then on Assets to see the complete list of deployed assets listed by asset ID. Follow the same process to see the existing assets on Statemine for Kusama ecosystem.
Moreover, in the Polkadot.js/apps UI, if you go to Developer tab, and click on Chain State you can query the state of the chain for the assets pallet to see the entire set of parameters and metadata for each asset (by asset ID) with asset and metadata state queries respectively. In the screenshot below you can see all this information shown for the asset ID 21, wBTC.