Opening a bank account as a fresh immigrant before the age of neobanks was a nightmare. In my desperation I even called a private bank in Jersey only to be told a need a whopping 5M pounds deposit to open an account.
After visiting 20+ branches in person in London, one manager took pity on me and opened a business account.
I had all paperwork fully ready, they just weren't interested, or at least I wasn't aware of the 'dance' required to open an account. You couldn't just walk in an open one. You needed an appointment for another day.
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.
