If anything it could help legal immigration. There's a bootstrapping issue where you need a utility bill to open a bank account and a bank account to get paid and get paid to pay the utility bill. And also need all 3 to rent a property to live in. You can choose the right providers to work around that with just your passport, but that involves a bit of work and research.
No idea how that would solve anything illegal though and realistically, I don't think they do either.
Most companies will not pay a local employee to an international amount. You're also going to pay quite large fees for any transfers if you wanted to pay bills. Also, the account abroad is not a proof of address in the UK which is the thing you want from statements.
Long time ago when I came to the UK I had that exact problem, there was only one bank (HSBC I think) that agreed to open an account for based on passport only. Even though I'm an EU citizen and UK was part of the EU at that time. Otherwise I would be stuck, because my employer (no employer I know of) would send my wage overseas.
No idea how that would solve anything illegal though and realistically, I don't think they do either.