Whilst they do have a cloud-hosted subscription service, the self hosted version is still available.
The newest version of the Windows app doesn't support creating or opening local vaults, only storing data in their cloud.
They also no longer offer perpetual/non-subscription licenses, including for the older version that supports local vaults.
At the very least the first would be a requirement for any sort of "self hosted" setup.
I ask because I use iCloud heavily. Nearly 1TB of photos/videos and now use 1Password with iCloud sync.
Has Apple made mistakes when designing iCloud, allowing unauthorized access to accounts? Yes.