It depends on what you mean by 'wont eat' and the quantity.

Horn wort did not do well as I recall.

I have had huge clumps of ceropteris floating with goldfish with excellent
restults. The trick is to have enough of it that it grows faster than they
nibble at it. They seem to prefer the softer old leaves as well.

Other rooted plants benefit from their going after this relatively soft
species first.

15 years ago, I had a 10 gallon tank with 2 goldfish, both ~4" in body
length, and no other plants, just good looking rocks. If the water sprite
took up more than 1/3 of the surface area, it was growing faster than the
fish ate it.

Once it got big, sending its longest roots all the way to touch the gravel,
I was pulling clumps out every few weeks.

In addition to benefits to water chemistry and diet, they also serve as a
healthy alternative to vacation fish food blocks. They ate more sprite when
they didnt get their normal food.

regards,
KL