I think a large part was:

• it’s a fork of infinity so it will likely diverge in looks/functionally

• it’s a different developer than Infinity

Niagara Launcher, fishicons icons

Another second for Fen, switched to it a few months ago and it’s been a smoother experience

The best reasoning I saw for this change was for clarity for non native English speakers. If you’re learning the language “allowlist” is definitely more clear in meaning than “whitelist”