Can be synced to the cloud of your choice. Even supports WebDAV, which is very lightweight.
Encrypted at rest and end-to-end. Those clouds don’t have your decryption key. Decryption happens in your browser client-side.
Cross platform. Anything that can load a webpage or is compatible with KeePass can use it. It can be bookmarked to the home screen on mobile and it becomes its own app.
Auto fill via hotkey on PC.
Supports PINs/Multi-Factor Authentication codes.
Can attach secret files like backup codes or SSH keys.
Can configure how strong the encryption is on the KeePass file.
Theme support.
Secrets can be exported.
Edit: in another comment someone mentioned the KeeWeb developer is looking for another maintainer due to their own personal health issues. It’s been stale since mid-2022, while the core is considered still secure there is concern for its dependencies. It can be compiled at home with updated dependencies if that concerns you.