Sega just brought their own demise in the console business when they tried to prolong the genesis lifespan by its addon (32x, Sega CD) when they would be releasing Sega Saturn 6 months later

the price, the hassle (each addon required its own power supply) and the lack of games developed for that system after that took a toll on their finance and eventually ended their fight in the console wars after not so good sales of their final console, the Dreamcast.