The hard part opening a bank account in UK as a fresh immigrant is providing a proof of address. The easiest way is to show your NINo paper (SSN equivalent). It will take you about 3 months to get that paper, so you need to manage somehow without a UK bank account during this period.

I had no problems, opening the account online and only showing up to the branch for the final papers, but I had that NINo paper. Maybe you chose the "wrong" banks? Some like Lloyds are much more accommodating to immigrants and have few requirements.