do I really need these filters for the cat fountain or is this a scam?

I guess I can't paste pictures and I don't want to paste an Amazon link for fear of removal to appear to advertise.

But of course my princess cat needs the automatic water fountain that we love. They want us to replace filters often which is fine if it's necessary. I live in California and I drink tap water, idk.

You seem like the cat people, do I need to buy these filters for her automatic water fountain? The light keeps blinking at me. Thank you.