Why can’t RN die within 10 years? Because it’s been around since 2013 vs 2017? Because you like one more than the other?
I have concerns about Google’s commitment to Dart/Flutter, but I’m not sure one scenario is pants on head insane and the other just fact.
If for one technology you can extrapolate from today out to the next several years at least, and the other's path is effectively entirely opaque and at the whim of another party, it's a company-killer level risk to bet on the latter. Put it this way, if Google drops Dart/Flutter tomorrow, Google will be just fine as they have very little skin in the game so to speak. Technical reasons one way or another are completely overshadowed by the business risks, as the landscape is today (which will change over the years, but Shopify is making their decision today).
I'm not convinced it's a worse idea to guess lottery numbers than to guess what will be successful languages. To that point however, React isn't a language (or a framework) it's a library.
I would say Google has more to lose by dropping Dart and Flutter as a language and frame work than Facebook has/had by dropping React.