How many people are doing a spring cleaning of unused passkeys in their password managers? We're talking like a kilobyte of data, nobody needs to delete these things in any kind of normal circumstance.
Sure, it would be great if users would store 5 copies of their encryption keys, with one in a lockbox on the bottom of the ocean. But that's just not going to happen at any kind of scale, so an automatic way of putting encryption keys in a replicated password manager makes sense. And compared to how people normally handle end-to-end encryption keys, it's going to result in a lot less loss data in practice.