I address that at the bottom of my post. Keepass is the original, KeepassX is the Qt rewrite. KeepassXC got Qt 5 support, a bunch of misc QOL improvement patch

I address that at the bottom of my post. Keepass is the original, KeepassX is the Qt rewrite. KeepassXC got Qt 5 support, a bunch of misc QOL improvement patches, is actively maintained (unlike KeepassX) and also received some nice extra features such as TOTP 2FA support. It's a superset of KeepassX, so there's no real reason to use KeepassX at this point.