Using a bank or financial institution as a Trustee is an option that some Trust donors prefer to utilize. Doing so can offer financial expertise, continuity of trusteeship, etc.
As a matter of course, financial institutions typically charge a fee for providing such services.
If the Trust in question permits a Trustee other than the bank to be named, then a Trustee other than the bank could be appointed.
The terms of the Trust document itself dictate who can be appointed to serve in the role of Trustee, so read the document carefully.