Or rather in the case of Nintendo its 1st party games, for example the PS2 actually thrived more on it's 3rd party titles than anything else.
Like I said, it doesn't matter who owns the IP. Software is paramount -- whether that software is games, or movies, as you have rightfully pointed out. The PS2 benefited even more from being a DVD player than the PS3 did as a Blu Ray player. More recently, I think there are a fair number of Playstations and Xboxes that were bought at least partly to be a Netflix box.
The silver lining of the Wii U's years is that Nintendo somehow managed to tap into indie games right around the time that they really started to flourish (IMO), complementing its first-party titles and filling in for the absence of big third party titles. Perhaps I'm mostly speaking for myself, but I think quality indies are more suitable for the "Nintendo audience" than contemporary games from the major third-party publishers anyway -- a better fit for what kind of games Nintendo fans want to play. It wasn't enough to carry the Wii U, but the trend has carried over to the Switch, which has reportedly been a goldmine for a number of indie developers.
I have my Switch for both first-party titles and indies (as well as "smaller" third-party games like
Octopath Traveler), which leaves very little for my PS4 to scoop up aside from driving/racing games, with the occasional outlier like
Ace Combat 7. It's not all first-party games anymore.
They had a large misstep with the Wii U and probably tried to consolodate the hemorraging of money and started this youtube policy. Hopefully with the succes of the switch they will change their policy if they want Nintendo Online to be succesfull. Without streamers embracing online gaming with Nintendo, I dont see how Nintendo Online will ever reach the succes of PSN and Xbox. The runaway succes of Fortnite is, in part, because streamers on youtube/twitch embraced the game.
Nintendo Online needs more than just Nintendo relaxing their YouTube/streaming policy to reach the success of PSN/XBL. It needs better functionality with your friends list, game invites, messages/chat, etc., and some more online-dependent titles to justify the subscription.