YouTube App Keeps Crashing on iPhone 5

In order to play the latest version of the YouTube app on your iPhone, your phone needs to run a newer version of iOS. Unfortunately, an iPhone 5 cannot be upgraded past iOS 10.x. As such, you would need to get a newer iPhone model. At this time, at least, an iPhone 6s or newer.

Well if it doesn’t let you update, that’s because Google dropped support for iOS 10 with their YouTube app. Your phone was released in 2012, almost a decade go, hence they have removed support for iOS 10 it seems.

Sure you can contact Google support ... but I don't think they will continue to support older versions of their apps.