I was born in Germany and have a German passport. When I was a teen my family moved to the US and and have since also gotten my American citizenship. I have been considering moving back. I talked to my aunt who lives in Switzerland who told me not to bother trying to open a Swiss account it’s virtually impossible as long as you have a US passport. Germany is slightly better but at most there are 2-3 (mainly online only) banks where you might be able to get a basic (ie bare bones) account.
The IRS has the ability to compel foreign banks to freeze assets of US citizens living abroad or at least to make it a paperwork nightmare for them. I can understand why a company might not want to promote an individual to senior positions if banks are weary of dealing with them.