IMO Sega’s problem was started by having a confusing lineup of too many products. Then they fumbled the US Saturn launch and faced stiffer competition than before. Then the Dreamcast was a victim of the PS2 _also_ being a DVD player, which made it a much more compelling option in its early days.

In this case, Nintendo has a large and dedicated fanbase, hardware that they (IIRC) sell at a profit, and a truly enormous warchest. They’ll be fine.