Market share in itself might not reveal the whole picture, trends on the other hand, do. What are the trends you see, which makes you say, that Google is losing the game? Where do you see any downward trend? If anything, there's an upward trend. It's recent news that Chrome OS was getting the second place after Windows on the desktop OS market, outselling macOS devices by two-to-one in Q4 2020.
Google owns a sizeable chunk of the online space. They don't just own the desktop and mobile search market and the browser market, but they own the biggest portion of the mobile OS and app market (Android, Google Play), the ad market (Adsense, Adwords, AdMob), they have Youtube, Gmail, Blogger, Google Trends, Google Analytics, Google My Business, Google Images, Google Docs/Sheets, Google Voice, Google Chat/Hangouts/Meet, Google Maps, Street View, Google Pay, Google Translate, Google Photos, Google Cloud, Google One, Google Drive, Google Fiber, Google Home, Google Nest, Chromecast, Google Fit, Wear OS, Android Auto, Android TV, Chrome OS, Google Pixel, Stadia, reCAPTCHA, a plethora of dev tools and the list goes on with more than 100 of their products total. Many of these brands are leaders in their own category.
Nokia and none of the other companies you listed, was anywhere near as big and diversified as Google is now. There's no point in comparing those to Google, it's a whole different league. Nokia was/is a mobile phone manufacturer, telecom company and nothing more (ok, they made some CRT monitors too), Orkut and Myspace were social platforms and nothing more, Metacafe is a video platform and nothing more. Fun fact: Orkut was owned by Google in its later years. Google and social media is not the best mix apparently, apart from Orkut, Google discontinued Google Wave, Google Buzz and Google+ too. Nevertheless, Google is standing on so many strong legs now, no company ever came close to this.
You can hope of course, but the status quo isn't going to change anytime soon. With the sheer amount of data and information in Google's possession, they aren't in the position to lose. You wouldn't want to stand on one leg until they do.