Why was the PS1 so successful despite being a newcomer?

[Leynos]

SEGA, MS, Nintendo, and Sony all had some gaming experience before becoming console makers. SEGA with Arcades. Nintendo with Pong machines, Game & Watch, and Arcades. Sony worked with SEGA and Nintendo on games and hardware. Microsoft had the MSX in the 80s and PC gaming. So none were new to the industry. They had an idea of what to deal with going in.