This isn't my experience. Low heat (which is how you should be using them) and soft utensils (I prefer to use those anyway) should be enough to keep it going - I have no scratches or wear on mine that I've noticed, though I did just replace them. They're quite cheap so replacing isn't really onerous either.

> Unless you’re trying to avoid using oil for some reason

I don't want my eggs to be particularly oily, or if I'm explicitly making a buttery french scrambled eggs I want to use butter and I want to add it in later, not use it for lubrication/ stick. You'll need much more for the cast iron.