Short answer: a Peekaboo Cave does the same job a cardboard scratcher does — gives your cat a surface they want to dig into — but without the constant mess, and it lasts far longer.
Cardboard scratchers work because cats destroy them. The scratch feels satisfying precisely because the material flakes apart, which is also why you're sweeping shredded cardboard off your floor within days and replacing the whole thing within weeks. The dense non-woven felt on a Peekaboo Cave gives claws that same resistance to sink into, but it holds its shape instead of disintegrating — so one cave typically lasts months where a cardboard pad lasts weeks, and it doesn't leave a trail of confetti behind.
There's a cost angle too. Cardboard is cheaper up front, but replacing it every few weeks adds up quickly; over a year, one Peekaboo Cave usually comes out ahead of a running stack of refills.
And it isn't only a scratcher — the same cave doubles as an enclosed den your cat can nap and hide in, so it earns its spot in your home in a way a flat cardboard pad can't.
Is cardboard ever the right pick? If you want something disposable and ultra-cheap for a short-term need, it's hard to beat. But if you're tired of the mess and the constant re-buying, that's exactly the gap the Peekaboo Cave was built to fill.