Wings are on their ninth season of rebuilding (which began when they turned into sellers at the 2016-17 trade deadline). Larkin was 20 when they started to rebuild and he'll turn 29 this summer.
They'll probably get good soon enough as Seider/Raymond/Edvinsson are all good and they have some room for improvement with that trio and more prospects that should push through in the form of guys like Cossa, Kasper, Danielsson, Sandin-Pellika, Brandsegg-Nygard, but the question about their ceiling does remain with Larkin age 28, DeBrincat age 27, Kane age 36, Compher age 29, Tarasenko age 33 as players to replace or that have likely played their best or close to best hockey.
To say it's been slow, as they've plodded along hoping to rebuild through the Draft, is an understatement. The lack of a Homerun Pick outside of the top of the draft has made the plan difficult to execute. They drafted Filip Hronek in the 2nd round in 2016 (pre-rebuilding) and since then their most productive NHL players to date after the first round have been 2018 Jonatan Berggren (53 career points), 2017 Gustav Lindstrom (35 career points), 2019 Elmer Soderblom (16 career points) and 2019 Albert Johansson (7 career points)