At the current level, stems cells are used to create fully functioning organs, blood vessels, skin, ears, noses, eyes, bone marrow, spinal cords etc. starting at the cellular level.
Stem cell therapies are currently being used to treat diseases and cancers, again at the cellular division stage and going from there to create new cells to treat said diseases etc.
Stem cells in a topical skin care products like anti-ageing creams won't work, as the stem cells for new collagen and new skin are needed to be created at the cellular level and grown under laboratory conditions and then transplanted via injection or grafts.
Say pharmaceutical or skin care companies put active collagen stem cells in anti ageing creams, those cells need to penetrate the skin then they need to divide to create new collagen. But here's the problem...
Those stem cells will be dead sitting in a jar full of cream. Even if they encapsulated those cells in nano-capsules (which can penetrate the skin) (L'Oreal has been using nano-capsules for 15+ years in their skin care creams). Still, those stem cells will be dead, thus no cell division to occur to create new cells to grow new collagen or new wrinkle free skin. Then there is the problem of replacing your existing damaged cells.
Even if you see these claims on anti ageing products, it's a marketing ploy.
Sorry folks, there is no fountain of youth in a jar, not just yet. Perhaps in a few years in combination with DNA and gene therapies there will be. Research is always on going in this field.