Well both times Nintendo did so, they offered something the competition did not. Motion control with the switch and hybrid switch. Not to mention the huge nintendo library.
Scarlet on the other hand sounds like a carbon copy of the ps5 but without the ps library. If both ps5 and scarlet end up to similar again like ps4 and x1, then people will default to PlayStation cuz they have a prooven track record and MS is known for abandoning consoles mid gen.
MS still has the opportunity to learn from their mistakes with the Xbone and produce a more appealing product next gen. They may not necessarily outsell PS5 but they can still be a lot more successful than this gen simply by not making the same catastrophic missteps like launching underpowered and overpriced, the atrocious PR, etc.