YouTube is still best when it comes to streaming videos content for games, watching movies, and more but did you know that recently YoutTube App is left support for iPhone 5 which is not good for users who still hold iPhone 5 nowadays and this is not the first time already happened with older iPhone such as iPhone 4,4s
So, what to do know as most of you notice that it now requires an update which cannot be done with the lack of iOS 10.3.4 no matter you installed via compatibility still requires an update

Why YouTube App Requires an Update
Most apps often update to ensure the security and bugs fix for apps which give apps work more stable and bug-free while you also need to understand that you are using an iPhone which is so far old about 10 years which is again very old now which may one of the reasons why YouTube for iPhone 5 shows requires an Update
How to Watch Youtube for Now
I Know wired but the reality is YouTube app is no longer working for now iPhone 5 owners which don’t mean that you can’t watch youtube all you require the web browser in order to watch your favorite content for now and still there is no option to watch Youtube via the app but it’s working perfectly on “Safari”
Is there is alternative for YouTube
I research what I found is that in most other streaming services which offer limited content when it compares to YouTube however you can watch music videos and news as well but still it also limited with some of the other streaming apps such as Vimeo & Dailymotion

You can use an alternative like Dailymotion which again works as a compatible version, not as the latest version which still there is no guarantee when it stops working on the iPhone 5 on average most the basic apps require iOS 13 so you need to plan to upgrade your iPhone to latest iPhone or which runs YouTube