I feel like people who frequently make starters, are by and large just busybodies who really enjoy the science behind brewing, and just always have to have something going on in their little laboratories. From my experience, there is virtually no reason to make a starter for 95%of the beers most are brewing, and the money saved is minimal in the grand scheme of things. If you enjoy doing it, knock yourself out, but it’s usually overkill IMO.
I am sure people say the same thing about people that use fermentation temperature control, or adjust their water chemistry/pH, or do closed keg transfers, etc. I am not sure if you are talking about dry yeast or liquid yeast or 100B cell liquid yeast vs 200B cell liquid yeast. In my mind, fermentation is the most critical stage to making good beer. There are a number of factors in play, but pitching an adequate amount of healthy yeast is one of them. A 3 month old pack of White Labs or Wyeast will often ferment out fine (often after a long lag) and this is especially true if the wort is well oxygenated and using temperature control. There is often a good chance that fermentation will take an extra week, or you won't hit the attenuation target, or you won't have enough healthy yeast to clean up off flavors.
I don't make a lot of starters myself. I get around this by making 2.5 gallon batches, or using dry yeast, or harvesting and repitching yeast. Making a starter with a pack of Wyeast or White Labs is a very simple step towards consistently making better beer.