You’re not being silly, your concern is real. I bought my Bam a stuffed dog bed and the same night he got it, he made like 50 holes in it. Luckily he didn’t eat it, but he might have. You just never know with a bunny. We have a member whose bun ate a bunny igloo and sadly didn’t make it. The main culprit in that case was a poisonous textile dye.

I use vet beds for my buns. Here’s an example of a vet bed: https://www.amazon.com/American-Pet-Diner-021FLUS4030-Flag/dp/B006YY0HE0
It’s thick sherpa fleece with anti-slide on the underside. I buy big pieces and cut them to size. I don’t have the pattern of the US flag, they come in all kinds of colors and patterns and they are sold for dogs. A good thing about fleece is that it doesn’t have threads, so if a bunny does take a bite, the chances of the material passing right through the GI canal is much better than for woven fabric.

It’s good to put fleece over carpet, buns like fleece, it’s soft for their feet and they can dig in fleece and make fleece mounds, so it provides them with activity as well. One of my buns like to pull a fleece blanket into a cardboard house and then pull it out again. It seems like he finds it very meaningful.

I have two types of dog beds that I use for the bunnies. One is a soft bed with high sides and the other is one of the ones with a metal frame and canvas stretch across. In both cases they’re only accessible during supervised out of cage time, and I would take the soft one away immediately if there was much chewing happening to it. Fleece and vet bed are both great options.

My bunnies have memory foam mats in their condos which work well. You’d need to monitor anything like a mat or bed for chewing. I did try a dog bed once and Bindi kept peeing on it. He doesn’t do that with the mat.