I could open multiple, but then every month I'd need to spend time transfering money to each to earn the interest. Im not sure that would even count towards deposited every month, they might want to see a direct debit that is actually a salary. I'm not sure.
Further, I have an ISA (which is the UK tax free saving accont), that earns under 1% too and I'm limited to £20k a year into that account.
I have another account that pays ~2.x% per year, but on that one I'm limited to £250 a month.
Interest rates are abysmal right now in the UK.