Star citizen isn’t an example of an open beta that got stretched out. It’s an example of a scam.

A game of similar scope to star citizen is starship simulator, except that isn’t a scam and, oh look, it’s making surprisingly better progress (there still isn’t anything to actually do in it yet but it’s much further along in much shorter period of time). You can tell it isn’t a scam because people aren’t being asked to pay extra to access some more unfinished content.