Cruises typically only spend one day in Skagway. This with several other one-day stops.
Most will sell a trip on the White Pass as a day trip/excursion.
When I was there in May '22 I took a morning trip and then had the afternoon to walk around Skagway. The NPS visitor center and its displays is right at the foot of town. The volunteer support group for the NPS park has a nearby bookstore. I walked up to the town's history museum and then checked out several of the shops in town.
I was up there back in Oct. 1976 and the commercial part of town has changed/expanded, Plenty of shops and eateries for the tourists off the cruise ships.
Brian Norden