I use a service called cooksmarts.com (weekly recipes so you only have to shop and cook, very little planning) and they use an optimized timeline. I.e. everyone

I use a service called cooksmarts.com (weekly recipes so you only have to shop and cook, very little planning) and they use an optimized timeline. I.e. everyone takes a different amount of time to do certain things so there is room for mistakes. That's my best guess for why recipes don't have a timelines. You're also probably cooking more than one thing at a time I.e. entree, sides, desert etc. If each of those had their own timelines you'd be screwed.