You can also store a KeePass DB in cloud storage for synchronization across multiple devices, and as long as you have a strong password it is secure. You can further improve security by going to the database settings, and increasing the number of transformations necessary to derive the master key from your password. This will make your DB harder to brute force, but will also increase the amount of time it takes to open and save.
If you don't trust cloud storage providers, you can self host a Nextcloud or Seafile instance for your file-sync - or use syncthing, which is serverless.