I see what you're saying, but no one is immune. As you can see from your graph, Nintendo went into loss for years during the Wii U. That can kill a company. What would've happened if the Switch wasn't as successful? Or say they made another device that wasn't as successful and hit them hard like the Wii U?
But back to my main point, Sony's entrance into the console realm did the biggest disruption in console history imo. Nintendo had a headlock on the industry for many years, with SEGA trying hard to break that. Even Atari suffocated. Then came Sony and disrupted that whole system. Heck even Bill Gates saw PlayStation as a threat to his Windows, being in every living room. Imagine that. That spurred the creation of the Xbox.