I'm not sure I'm confident that the popular (and being fair, strong) engineering orgs don't make the decision first and work backwards justifying it like most of us do.

I have no specific exposure; but the rumour is with several big tech, it's write everything from scratch ( because we're special ), only reward impact ( rewriting from scratch ), and then shut it down because you can't maintain the thing ( too expensive because we keep rewriting it from scratch ).

Is it like that in reality? I dunno, but we all have our problems.