With rollups being great, what evidence is there that more scale is being achieved?

With Rollups being a key scalability focus – available today for cheap and fast transactions as well as a key part of the ethereum future – what evidence is there today for rollup adoption?

What metrics do we watch to say it’s being adopted successfully? Does it just appear in TPS graphs? Should that start going up or due to the way Rollups work it won’t exactly? Can we target rollup volumes somehow?