Today, I threw out https://buttercup.pw/ in favor of https://keepassxc.org/ - works flawlessly. Buttercup’s Firefox plugin regularly did NOT do what I wanted, the install is 200+MB (wtf? Oh, Electron…) and it consumes more memory than KeePassXC. I held off using password managers for a long time because I feared the server-sync thing, but both mentioned managers simply allow you to create a local DB. 👍
Also posted on Mastodon by Wouter Groeneveld.