> Marks of maturity of a project - acknowledging upgrade requirements, publishing upgrade guides, supporting previous versions for a publicly stated time range,

> Marks of maturity of a project - acknowledging upgrade requirements, publishing upgrade guides, supporting previous versions for a publicly stated time range, etc. All of which did happen for AngularJS. And you could still be using your AngularJS components within an Angular application today - or vice versa - thanks to the tools provided to migrate piecewise. End of life for AngularJS was only five months ago after a four year LTS period that started in 2018, given that Angular 2 was released in 2016 that's a five and a half year period where both frameworks were supported. Libraries deciding to break everything without warning is definitely an issue that's caused me grief in the past. Moving from AngularJS was something we decided on and planned out well in advance.