There is no such thing as a “nonpartisan panel” under the current political alignment. The kind of people who participate in such labels are invariably high trust, high education types. If they’re republicans, they’re Liz Cheney types rather than Trump types. If they’re Democrats, they’re Elizabeth Warren types rather than Bernie Sanders types.
Sure, but there are requirements in place to address some of those things. The commission can't be more than half+1 of the same political party, has to include a mix of lawyers and non-lawyers, etc. Compared to blatantly partisan judicial selections in other places, I think this system works pretty well.