Tangentially related question: What is the [recommended|best|most used] iOS KeePass client? The KeePass site recommends MiniKeePass that's been archived for a couple of years already.
I'm a very happy user of strongbox: https://strongboxsafe.com/
I currently sync my vault via WebDAV and they even support storing the local keyfile.
Same here. Nextcloud to sync the database, and a local keyfile that doesn't touch the internet/cloud.
It's also open-source under AGPL, though iOS doesn't have anything like F-Droid to verify builds.