Yeah, totally. It would become one of the most succesful third party, if not the most succesful. However, I still want their hardware. Not only because I like what Nintendo consoles offer as an entertainment system, but also because I think that having their own space where they can do whatever they want is what keeps Nintendo being Nintendo. If they went third party I believe its games would be different. I'm not talking about better or worse, but different.

every former console manufacturer failed after going 3rd party

None of that former console manufacturers had as many huge IPs as Nintendo. Not even close.

Probably better than Sega

They wouldn't just survive, they'd dominate.

They would survive in the same way that Sega survived.

Like an undead corpse.

One thing i want to point out about comparing Nintendo to Sega/Atari is that neither of those companies had nearly as many big hits as Nintendo. Atari never had any huge, long running franchises and other than Sonic, most of Segas were relatively small and niche.

That being said, i dont want Nintendo to go 3rd party because im not sure if they would continue to make their niche & more experimental software or just stick to the proven sellers. They would no longer need to support a platform so there would be less need for them to diversify their lineup.

Absolutely no.

They would be fine. But a lot of the series' that fans love and buy nintendos consoles for would probably be too risky and would never be made again (see Sega)

SEGA, SNK, Atari having no huge IPs? They have no huge IPs now because they failed commercially to transition to third party but at the time their IPs were quite huge. Look also at Capcom or Konami, owning huge IPs dont mean necessary sucess these days