Is there science on this? My March 2nd starter is plenty flavorful and pungent. You throw away (or find another use for) virtually all of it daily, so it seems an odd claim; after a couple days the original starter cells are basically at homeopathic levels of concentration.
The taste of the starters comes from whatever you feed it and environmental conditions.
Personally, I’ve tried sourdough a couple of times, never gotten the starters to really work (despite having done tons of other bread). I’m trying it again now, but I’m kickstarting the starter with pickle brine (not vinegar, the actual lactic fermented brine). There’s some bacterial activity, but it’s too soon to tell if it’s going to work.
But in the meantime, I’ve got a yeast starter going from my last commercial yeast, because I’m out of yeast and so was the store. It’s been going a week now, and it’s working reasonably well, and even getting a bit sour, with none of the problems of weak rising that you can get from a more pure sourdough culture.
having a few jars that you cycle through every feeding removes the funky crusty buildup that tends to happen if you reuse the same jar.
If I decide to give it another go I’ll definitely do that. Good idea.
Worst case, you can augment your rise by combining your starter with a portion of industrial yeast when baking. You get the best of both worlds. Flavor from the starter. Rise from industrial yeast.
The flavors are pretty surprisingly similar but not exactly the same. The older one is a little more complex or something but I'm not sure most people would know the difference, especially if you didn't tell them.
Once a levain/starter gets going it's usually pretty stable I think. Maybe older cultures are more resistant to prolonged shocks, but I think it depends on the case. In general I have a theory that older cultures are an opportunity to evolve them to different conditions, like time between changes in storage conditions (which might affect things like rising time), alcohol levels (useful for sugar levels in breads), temperature, etc.