Struggling with Cattail — would appreciate advice

I want to be honest: I'm not getting great results with Cattail and I'm not entirely sure why. root-eating by water lily aphids or china mark moth has been a recurring problem despite my attempts to address it. I've been focusing on removing dying foliage in autumn before it rots and reduces water quality based on everything I've read.

natural filtration improving water clarity and quality is there in glimpses, which tells me the plant has potential in my conditions. I have it in a natural wildlife pond with naturalistic marginal planting which might not be ideal. peak flowering period in midsummer showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.