Since you mentioned it, I was always curious if the team behind TablePlus were/are connected to the team behind Postico [1]. The UIs for both (at least before Postico 2) are almost identical.
It'd been several years, but taking another look now I can spot the differences.
I suppose the tooling for databases (or the expectation from users) means they all end up sharing a similar UI and where and how various features are implemented. Not too unlike word processors or spreadsheet software!
They came first, I wouldn't say I copied them, but we both value good UX and app design. I actually copied an old Mac app called SequelPro, which I missed greatly when moving to PSQL and a Linux desktop OS :-).
When I started building Beekeeper there were 0 open source DB apps with good UX, especially on Linux. So that's why it exists.
I now have a paid version to support development as it has grown super quickly over the last 3 years.
[1] https://tableplus.com/